NZ208123A - Sizing agents for cellulosic products - Google Patents

Description

208123 Priority Date(s): Complete Specification File/d: Class: C.?.lKX . 3) ?/<?.?..........

Publication Date: P. A?fl J?P7..... P.O. Journal, No: NEW ZEALAND No.: Date: WKTITUTHM OF APPUCAKT WISER SECTION 24 ■ lioC.

PATENTS ACT, 1953 ~U 1 Fr.

COMPLETE SPECIFICATION IMPROVED SPRAYING PROCESS FOR MAKING SIZING AGENTS FOR CELLOLOSIC PRODUCTS 31 / We, TH&-PLASMINE-e©RPORATiQN-, incorporated in the State of Delaware, United States of America/ located at 61 Bishop Street, Portland, Maine 04103/ United States of America hereby declare the invention for which Xx/ we pray that a patent may be granted tojgjeg?/us, and the method by which it is to be performed, to be particularly described in and by the following statement: - (followed by page la) -ICL~ SIZING AGEHTO TOR GCLLULOCIC PnODUCTO This invention relates to new and improved sizing agents. More particularly this invention relates to new and improved sizing agents prepared from a specially 5 modified rosin component and an ammonia and ammonium salt-providing material such as ammonia, and ammonium salts, or their precursors, or reaction products of urea with a Lewis acid such as sulfuryl chloride, para-toluenesulfonyl chloride, and the like. Such sizing 10 compositions exhibit especially advantageous sizing properties due to both the nature of the components ■ employed and the manner of combining such components.,.

Cellulosic products—paper, rigid paper, paperboard, molded products, and the like—basically are 15 produced by applying a dilute suspension or solution of fibers in an aqueous medium onto a fine mesh screen through which the aqueous medium drains, leaving a thin mat of fibers. The mat is removed from the screen, further liquid is expressed and the sheet is dried to 20 form the desired product. The fibrous raw materials used in this process are generally one or more of the several types of commercially available pulp. These pulps include mechanical pulps, or groundwoods, bleached or unbleached, and chemical pulps, for example bleached, 25 unbleached, and semi-bleached sulfate and sulfite pulps, as well as semi-chemical pulps. Other fibrous constituents used as the fibrous paper and paperboard-making raw materials include reclaimed waste papers, cotton fibers, inorganic and synthetic organic fibers, and 30 mixtures of these materials. 208t 23 The first step in paper product manufacture is pulp stock preparation. Pulps are most conveniently handled in slurry form to facilitate their mechanical treatment, non-fibrous additive mixing, and their 5 delivery to the paper machine. Pulps are fed to the paper mill in a slurry directly from the pulping operation where both the pulping and paper-making are performed at the same location; otherwise, they are received as dry sheets or laps, and must be slushed 10 before use. Slushing separates the fibers and disperses them in the aqueous medium with minimum detrimental mechanical effect so as to produce a consistently uniform starting material. The pulp slush or slurry is subjected to mechanical action known as beating or refining before j 15 being formed into a paper sheet. During refining, the fibers are swollen, cut, macerated, and frayed controllably to produce smaller fibrillar elements and to thereby desirably affect the physical properties of the resulting end product. Unbeaten pulp produces a light, - *20 fluffy,-weak paper, whereas well-beaten pulp - yields * stronger, denser paper; During the beating or refrnimr— process, many non-fibrous materials are added to the pulp solution. Among these are mineral pigments for filling and loading, such as kaolin, titanium dioxide, calcium 25 carbonate, and other well-known filling materials, coloring additives and dyes, sizing agents, and other known beater additives.

After the pulp slurry has been beaten and refined and the additives mixed into it, this pulp slurry or 30 "furnish" is delivered to continuous sheet-forming equipment, such as a cylinder machine or a Fourdrinier, where it is discharged onto fine mesh screen through which the liquid carrier or aqueous medium drains and on which a fibrous mat is formed. This fibrous mat or sheet 35 contains, for example, about 80 percent water when it 1 3 leaves the screening and is therefore passed through one or more rotary presses for more water removal and is subsequently passed through a drying system, for example, steam-heated rotating cylinders, to yield the finished product. Molded pulp products are made on different equipment by a similar process designed to form, dry and press individual molded items such as paper plates and the like.

The sizing agents, as mentioned, are added to the paper-making process pulp slurry so as to render the finished product resistant to liquid penetration. In the alternative, the sizing agents may be excluded from the pulp additives, and may be applied to the paper after it is dried and has very effective penetration resistance. In this method, the dry sheet is passed through a size solution or over a roll wetted with a size solution.

Such sheets are "tub-sized" or "surface-sized" respectively.

Among the materials currently used as sizing agents are rosin, various hydrocarbon and natural waxes, starches, glues, casein, asphalt emulsions, synthetic resins, and cellulose derivatives. Rosin is one of the most widely used and most effective sizing agents. Extracted rosin is often partially saponified with caustic soda, and processed to yield a thick past of about 70 to 80 percent solids, of which up to about 30 to 40 percent is free, unsaponified rosin. Dry (unsaponi-fied) rosin and completely saponified rosin are also used as sizing agents. Any of these rosins may further be modified, for example, by the addition of maleic anhydride or other supplement. At the paper mill, the rosin paste is dissolved or emulsified by diluting it to about 15 percent solids with hot water and then further diluting it with cold water under vigorous agitation to about 5 percent solids or less. This solution or dis- 20812 4 persion is either used for surface-sizing or is added to the paper stock, for example, about 0.1 or 0.5 to 4.0 percent size based on dry fiber, usually before, but sometimes simultaneously with, for example, 5 about one to three times as much aluminum sulfate (paper-makers alum). The aluminum sulfate is believed to form an ionically-charged precipitant with the rosin size which is attracted to oppositely-charged fiber.

Recently, it was discovered that novel sizing 10 compositions can be produced which are more effective than the well-known types and which are compatible with presently used pulp and stock material and additives. Certain of these sizing compositions are disclosed in U.S. Patent 4,022,634, issued May 10, 1977, to Emerson, 15 et al., incorporated herein by reference. These sizing compositions contain a specifically modified rosin, ammonia and an ammonium salt. Other sizing compositions which exhibit these improved properties are disclosed, in U.S. Patent 4,141,750 issued February 27, 1979, to 20 Enfgfson, et al., incorporated herein by reference. These sizing compositions also contain a specifically modified rosin, ammonia, an ammonium salt, and additionally include the reaction product of urea with a Lewis acid such as sulfuryl chloride, para-toluenesulfuryl chloride 25 and the like, which urea-reaction product may provide part of the ammonia and ammonium salt essentially present in the compositions.

It has now been discovered that sizing compositions such as those disclosed in U.S. Patent No. 4,022,634 and P»_SA„..gafcjsnt No..—4-r1-4~1-y-750 can be provided which exhibit sizing characteristics that are significantly improved even a compared to the compositions made by the techniques set forth in those disclosures. These improved sizing compositions are provided by 35 combining first and second components of such composi- 20812 tions while the second component is finely-divided into liquid or solid particles, and controlling the time of reaction of these components to obtain the desired result. In one embodiment of the invention, the first component may also be finely divided into either fine liquid or solid particles for combination with the finely-divided second component. Combination of composition components in this manner apparently accelerates the chemical reaction between materials in the two components, and this provides compositions which are surprisingly efficacious sizing agents.

The first composition component comprises one or more materials which provide both ammonia and ammonium salt when combined with other sizing composition components. This ammonia/ammonium salt-providing material is selected from the group consisting of ammonia, or a precursor thereof; ammonium salts, or precursors thereof; and reaction products of urea and at least one Lewis acid selected from sulfuryl chloride, chlorosulfonic acid, thionyl chloride, benzenesulfonyl chloride, benzenesulfonic acid, orthotoluenesulfonic acid, para-toluenesulfonic acid, ortho-toluenesulfonyl chloride and para-toluenesulfonyl chloride. Mixtures of these ammonia/ammonium salt-providing materials may also be employed. Ammonia, e.g., ammonium hydroxide which is an aqueous solution of ammonia, and ammonium salt can be employed as such in the first component, or precursors which produce ammonia and/or ammonium salt, e.g., in situ, in the sizing composition, can be used in the first component. For instances, as more fully described in U.S. Patent No. 4,022,634, the ammonia and ammonium salt may be produced as the reaction product of urea and an acid and, optionally, additional ammonia or ammonium salt may be added to the urea-acid reaction product, ammonia may be reacted with salt-producing ingredients, e.g., .... ,—„,■■■ I ■ ■■■■■— I III I 208123 6 acids, or the rosin to provide ammonium salt, or ammonium salt can be reacted with ammonia-producing ingredients of the rosin to provide ammonia. Acids which can be used to react with urea to produce the ammonium salt and which 5 may be present in the first or second component include sulfamic acid, and phosphoric acid, as well as oxalic acid, methanesulfonic acid, trichloracetic acid, nitric acid, sulfuric acid, hydrochloric acid, stearic acid and acetic acid. • The first component may also contain the reaction product of urea with at least one selected Lewis acid as more fully described in U.S. Patent No. 4^141,750. To form the reaction product, the urea and at least one Lewis acid selected from the group consisting of sulfuryl 15 chloride, chlorosulfonic acid, thionyl chloride, benzenesulfonyl chloride, benezenesulfonic acid, ortho-or para-toluenesulfonyl chloride, and ortho- or para-toluenesulfonic acid are mixed together and reacted. The preferred Lewis acids are sulfuryl chloride, 20 chlorosulfonic acid, benezenesulfonyl chloride and benezenesulfonic acid„ —If .water is present, it is advantageously included in amounts, parts by weight, approximately equal to the urea plus Lewis acid, although urea may be reacted with the Lewis acid using water in 25 excess of equal parts, or with little water or without water. If the Lewis acid is a solid, the reaction with urea may be carried out at a temperature somewhat about the melting point of the acid.

The urea is generally reacted with the Lewis acid 30 in such amounts and at a temperature sufficient to cause a change in the pH of a mixture from an acidic pH before the reaction begins to a basic pH a the reaction is completed as determined by a pH meter. This temperature will generally range from about 100°C to 215"C and is 35 dependent to some extent upon the water contents of the 7 mixture, and may generally be higher for mixtures having a low water content.

Although the pH change is an important indication that the urea-acid reaction is complete, a more important 5 consideration is the total acidity of the first component reaction product. This total acidity is measured as the amount of sodium hydroxide, expressed as the equivalent parts by weight of calcium carbonate, required to impart a pink color to a million parts of a phenolphthalein-10 containing, 50 weight percent, aqueous solution of the reaction product, and may be determined by use of the Chemical Company Total Acidity Test (HaCH Chemical Co., Ames, Iowa, Model AC-5 Acidity Test Kit). When the acid is<reacted with the urea, ammonia and an ammonium salt 15 are produced and this reaction not only raises the pH but alio affects the total acidity of the mixture. Although it is not fully understood, this higher first component acidity (higher than pure urea) is believed, in part, to account for the ultimate superior sizing composition, 20 i.e., agent, obtained. Thus, the amount of acid to urea is an important-aspect, and is best defined in terms of the resulting total acidity (ppm) which it creates. The desired minimum total acidity is at least about 1,000 parts per million, and is preferably at least about 4,000 25 ppm. The actual amount of acid reacted with the urea is generally at least about 0.1 percent, and preferably from about 0.2 percent to about 8.0 percent, based on the weight of the urea, although more may be used, e.g., 15 or 20 percent acid, based on the weight of the urea, to 30 achieve the desired results.

Reaction of the urea with the acid is preferably, but not necessarily, conducted out of the presence of the rosin and the organic acidic material used to modify the rosin. If desired, however, the urea can be reacted with i i — in Ml i i if - i iimi ■HillilW ' I I 208123 8 the Lewis acid while in admixture with the modified rosin, as more fully discussed hereinafter.

Optionally, amounts of additional ammonia, for instance up to about 6 percent by weight of the total 5 mixture of ammonia, water and urea-acid reaction product may be added to the mixture of the urea-acid reaction product and water after it has cooled to room temperature to enhance the sizing results achieved upon combination with the specially modified rosin. For example, 20 parts 10 of 29 percent aqueous ammonia can be mixed at room temperature with 80 parts of the mixture of the urea-acid reaction product and water. This mixture can then be combined with the modified rosin second component as more fully discussed hereinafter. - In another embodiment, an additional ammonium salt is combined with urea and a Lewis acid selected from trie group consisting of sulfuryl chloride, chlorosulfonic acid, thionyl chloride, benzenesulfonyl chloride, benzenesulfonic acid, p- or o-toluenesulfonyl chloride, -20 and p- or o-toluenesulfonic acid to provide sizing agents s ■ ~ of the present invention. The-additional ammonium salt- - -is in addition to the ammonium salt produced by the reaction between urea and the selected Lewis acids of this invention, and at least essentially the entire 25 amount, e.g., at least about 90 weight percent, of the ammonium salt formed through reaction with urea with an acid, is advantageously provided by reaction with the selected Lewis acids of this invention. The proportion on a weight basis of the urea to the additional ammonium 30 salt, if employed, may often range from about 2 to 1 to about 1 to 4, and preferably is about 1 to 1 to 1 to 4.

This reaction product first component may then be combined with modified rosin, instead of the urea-acid reaction product alone, to yield a sizing agent. 1 The ammonium salt employed in the first component of the present invention may be the salt of an ammonium salt-producing acid which reacts with ammonia to produce an ammonium salt such as, for instance sulfamic acid, 5 chlorosulfonic acid, phosphoric acid, oxalic acid, p-toluenesulfonic acid, trichloroacetic acid, hydrochloric acid, sulfuric acid, methanesulfonic acid, nitric acid, stearic acid, acetic acid and sulfuryl chloride. Solid preformed ammonium salts may be used, 10 or, alternatively, the salt may be formed by reaction of the desired acid with ammonia. Thus, for example, dry powders of ammonium sulfate, urea, and chlorosulfonic acid are heated together to about 160°C at which - temperature the mixture goes from an acid pH to an 15 alkaline pH of about 8 to provide the ammonia/ammonium salt-containing first component.

The second component of the sizing compositions herein comprises a rosin that is modified with an organic carboxylic acidic material which can be an 20 o,0-unsaturated organic acid, an anhydride of such an acid or mixtures of such acids and anhydrides. The -a,p-unsaturated acid or derivative can be, for example, an a,3-unsaturated aliphatic acid generally containing from about 3 to 10, preferably from about 3 to 6, carbon 25 atoms, as for example, acrylic acid, and those preferred include maleic acid, maleic anhydride and fumaric acid.

Rosin is a mixture of resin acids (including abietic, pimaric, and leopimaric acids), hydrocarbons and high molecular weight alcohols, which is obtained from 30 any of several sources. Gum rosin is the residue remaining after distillation of turpentine oil from crude turpentine oleoresin obtained from living pine trees, wood rosin is the residue remaining after distilling off volatile fractions of the solvent extraction product 35 (usually using naphtha as the solvent) from pine stumps, 123 y and tall oil rosin is a byproduct in the fractionation-of tall oil (an oily mixture of rosin acids, fatty acids and neutral materials obtained from the acid treatment of spent black liquor from paper and pulping processes).

All three types are very similar chemically, except that tall oil rosin often contains 1 to 5 percent fatty acids remaining after fractionation, whereas gum rosin and wood rosin do not. As mentioned above, rosin may be used in sizing agents in "dry" form, or may be partially or 10 completely saponified. In the sizing compositions of the present invention, gum rosin, wood rosin, tall oil rosin, or their mixtures, may be used. Tall oil rosin is preferred, however, as it generally produces the best results, possibly due to the presence of the fatty acids 15 in it, although this is not fully understood.

As mentioned, the organic acidic materials which' may be used to modify the rosin are a,0-unsaturated organic acids and anhydrides and their mixtures. Amounts of the organic acidic material used to achieve the ,20 desired results generally range from about 5 to 50 percent or more, based on the weight of rosin but preferably from about 5 to 30 percent is used, particularly about 15 percent. The modified rosin can be formed into a soap by known methods, for example, by 25 adding sodium hydroxide, potassium hydroxide, or ammonium hydroxide to form an alkali metal or ammonium soap of the rosin acids. Generally, the rosin can be saponified after it is modified. In any event, saponification need not be complete, but is preferably sufficient to render 30 the final sizing composition water soluble. With respect to the embodiment of the present invention comprising the reaction product of ammonia and modified rosin, ammonia is preferably used as one of the saponifying bases.

In accordance with the present invention, the 35 first and second composition components as described 11 hereinbefore are combined while the second component, and preferably also the first component, are in a finely-divided liquid or solid state or are finely-divided mixtures of liquids and solids. The second component and optionally the first component may be finely divided into particles which may be solid or liquid, i.e., droplets, by various means that will be apparent to those skilled in the art. Advantageously the average diameter of such liquid or solid particles ranges from about 10 to 1000 microns, preferably from about 20 to 250 microns.

In the invention, the reaction between the first and second components can be controlled in order to provide products of improved characteristics. Such control may be through the use of relatively short reaction times. The reaction time may be of the order of up to about one minute, preferably up to about thirty seconds, say about 15 to 30 seconds. The reaction time may often be about 10 seconds. A particularly effective manner of controlling reaction time and providing adequate mixing of the first and second components is to form a commingled-spray of these materials in the desired particle size range.

It has been found that conversion of the second component into fine particles can be accomplished by adding the liquid or solid second component to the first component while the first component in liquid form is subjected to high shear agitation in a blender or mixing apparatus. Addition of the second component to the agitated first component liquid serves to finely divide the second component as it contacts the agitated liquid. The blender or mixing apparatus agitating element can be operated at a speed that provides shear agitation which is sufficient to finely divide the second component being added into particles having an average diameter within the 10 to 1000 micron range. A Waring blender operating 208123 with a mixing element speed of from about 10,000 to 25,000 r.p.m. can, for example, be used to agitate the first component as the second component is combined therewith.

Alternatively, when the two components are in the liquid form, both components can be forced through spray nozzles and the two streams of spray combined in a suitable container. In this manner both the first and second components are divided into droplets within the 10 aerosol size range. Advantageously, the nozzles employed produce droplets having an average size of from about 10 to 200 microns, preferably from about 20 to 125 microns. As an example of nozzles which can be used successfully, the second component can be sprayed from nozzle No. ■ 49487650 manufactured by Spray Engineering Company, East . Spit Brook Road, Nashua, New Hampshire 03060, while the first component is sent through a similar full cone center jet nozzle also manufactured by Spray Engineering Co. Steam under pressure is a suitable gas for forcing 20 the second component through such a nozzle. "The first ■ component spray can-te formed -with -or -without using-a -pressurized driving gas. Streams from the two nozzles can then be combined to effect component mixing while both components are in a finely-divided state. 25 In combining the first component with the second. component to form a sizing composition according to the process of the invention, sufficient amounts of each component are used to provide sizing effective amounts, generally from about 25 to 85 percent based on the total 30 dry weight of the sizing composition, of the first component, and from about 75 to about 15 percent of the second component, in the sizing composition. The sizing composition made by the process generally contains at least about 25 weight percent, often about 40 to 60 35 percent, water. 12 2081 2 While the second component, and optionally the first component, is finely-divided according to the process into fine liquid or solid particles, the components can simply be mixed at room temperature. Less advantageously, these components may be mixed and heated to the boiling point of the mixture to assure that all reactions are completed.

When the first component and the second component are combined at an elevated temperature, the modified rosin may be heated to or kept at a temperature at which the combination may be carried out. This combining may comprise adding a diluted mixture of the first component reaction product, which is heated, to the heated second component, in order to effect chemical and physical mixing. The mixture of first and second components can be heated at about 212°F to boil off the water, and is preferably kept at the boil-off temperature until the cloudy solution becomes substantially clear. Optionally, after component combination is completed, very small amounts of ammonium hydroxide may be employed to adjust the pH of the product back into the basic range, i.e., to greater than 7 if it has dropped into the acidic range, i.e., below 7. Amounts of ammonium hydroxide, up to about 0.05 percent by weight of the mixture, will generally raise the pH to the desired range. The selection of first component and second component dilution concentrations prior to component mixing is dependent on the desired relative amounts of first component and second component and on the desired concentration of the resulting sizing compositions. The choice of combination temperatures employed is a function of workability and of the desired degree of chemical and physical mixing, although in an embodiment of the process, temperatures of at least about 80°F"may prevent precipitation on mixing. 14 1 2 After the first and second components are reacted, they can be contacted with aqueous solution of one or both of sodium or potassium hydroxides to obtain a product of the desired pH. Preferably, these bases can be 5 added in sequence, especially KOH followed by NaOH. The addition of the aqueous base can serve in essence to conclude the reaction of the first and second components.

As mentioned above, ammonia, an ammonium salt, and the specially-modified rosin or a soap of the specially-10 modified rosin can be prepared by pouring the hot mixture of the rosin and the rosin-modifying organic acidic material into an aqueous solution of a saponifying base, e.g., sodium hydroxide and/or potassium hydroxide, under slow agitation to saponify the modified rosin. Suffi- ' 15 cient aqueous solution of the saponifying base can be used to produce an aqueous mixture of modified rosin soap containing from about 50 to about 70 weight percent solids. Based on the total weight of the ammonia, the ammonium salt, and the rosin and the modifying organic 20 acidic material on a dry basis, the sizing agent may have from about 3-percent to about 30 percent ammonia,- from^^" about 4 percent to about 72 percent ammonium salt and from about 93 to about 25 percent rosin plus modifying organic acidic material, using a ratio of ammonium salt 25 to ammonia that is greater than about 1:1. The term "dry" is used throughout this specification to mean exclusive of any water which is present. The ammonia may be produced in situ by, for example, reaction between the rosin, the modifying organic acidic material, and the ~ 30 ammonium salt by using from about 4 percent to about 75 percent rosin plus modifying organic acidic material based on the total weight of the ammonium salt and the rosin and modifying organic acidic material on a dry basis.

The amount of ammonia used depends upon whether or not ammonia is the sole saponifying agent used. When ammonia alone is used to saponify the specially-modified rosin, about 10 percent to about 75 percent ammonia, and 5 from about 25 percent to about 90 percent rosin plus modifying organic acidic material based on the total weight of the ammonia and the rosin plus modifying organic acidic material on a dry basis, can generally be used to prepare the sizing agent. When ammonia is 10 reacted with a soap of the specially—modified rosin, -the mixture can generally be prepared with from about 4•-percent to about 60 percent ammonia, and from about 96 percent to about 40 percent rosin plus modifying organic acidic material, based on the total weight of the ammonia 15 and the. rosin plus modifying organic acidic material on a dry basis.

Procedures involved in the preparation of the sizing compositions herein, besides the aspect of combining components while the second component, and 20 optionally both components, are finely divided, are set forth in the specification of U.S. Patent No." 4,022,634 and U.S. Patent No. 4,141,7507 15cfth of which are incorporated""herein by reference.

The sizing agents of this invention have a pH 25 generally in the range of at least about 6.6 to about 10 or 12 and a total acidity of at least about 1000 parts per million. The pH is preferably at least about 8, say about 9 to 11. This total acidity is measured as the amount of sodium hydroxide, expressed as equivalent parts 30 by weight of calcium carbonate, required to impart a pink color to a million parts of phenolphthalein-containing sizing composition of the present invention, and may be determined by use of the Hach Chemical Company Total Acidity Test (Hach Chemical Co., Ames, Iowa, Model AC-5 35 Acidity Test Kit). The preferred objective of each of 208123 u 16 the embodiments of the sizing agent of the present invention is to obtain the highest total acidity possible without lowering the pH to a level which makes the sizing agent insoluble in paper mill water. Thus, the propor-5 tions of the ingredients of the sizing compositions of the present invention can vary in accordance with this objective and are thus conveniently defined in terms of the pH and total acidity they produce in the sizing agents.

These improved sizing compositions exhibit superior sizing properties compared to conventional sizing agents when used in the same amount, and equivalent properties can be obtained when used in lesser amounts, than the conventional sizing agents, thus • enabling the user to meet existing standards with less sizing agent than heretobefore required, and, therefore, at a lower cost. The products resulting from the use of the sizing compositions of this invention can be brighter-and stronger than those produced by the heretofore 20 available sizing agents. The novel sizing compositions also assist in the drying of the sheet when employed as a pulp additive so that the paper-forming machine may be speeded up to produce a sheet of the same moisture content. Alternatively, more water may be added to the 25 pulp stock to give the fiber on the paper machine wire a , better orientation, thereby producing a stronger paper with superior formation. The novel sizing compositions are normally employed alone as a sizing agent with papermaker's alum in pulp stock or in surface sizing, but 30 may be combined with various sizing agents to replace a substantial part of those known agents.

The improved sizing composition may be employed as a pulp additive or as a surface sizing agent in the manufacture of cellulosive products. The exact amount to 35 be used to produce optimum results may vary, depending 20812 17 upon the type of pulp used and the desired properties of the finished product. Amounts generally less than those currently used with known sizing agents may generally be used to produce substantially equivalent or superior 5 products. Thus, for example, while known rosin sizing agents are generally used in amounts from about 0.1 or 0.5 percent up to about 4 percent of solids based on the weight of fibers of the pulp slurry, the sizing compositions of this invention may be used in amounts as low 10 as about 0.05 percent or 0.25 percent. Thus, from about 0.05 to 0.25 up to about 4 percent of the sizing compositions herein, by dry weight based on the weight of fibers in the pulp slurry, may be used. Typically, where 1 percent of known rosin sizing agent is normally used, 0.5 15 percent of the novel agent of this invention can be used to obtain substantially equivalent or superior results.

Preparation of the sizing compositions in the manner specified herein also permits formulation of less costly compositions. This can be accomplished since less 20 of the relatively more costly components (e.g., the modified rosin) need be utilized to prepare sizing compositions which have sizing effectiveness substantially equivalent to compositions prepared in known manner which contain more of the relatively more 25 expensive components.

The methods of this invention are further illustrated by the following examples.

Example 1 The first component of a sizing agent is prepared 30 by placing 4,000 grams of commercially available urea, 200 grams of sulfamic acid, and 4,200 grams of water in a cooking vessel, and subsequently applying heat while slowly agitating the contents until the reaction mixture boils at atmospheric pressure. When the temperature 208123 18 reaches about 103°C, boiling stops, water losses cease, and the pH of the solution, as determined by a pH meter, rises to about 8. The resulting first component product is a clear solution having a total acidity of 86,000 ppm, 5 as determined with the Hach Chemical Company's Acidity Test Kit Model AC-5.

To form the modified rosin second component, 3,000 grams of commercially available tall oil rosin is melted in a cooking vessel. To the molten rosin is added slowly 10 with agitation the following ingredients: 360 grams of fumaric acid plus 100 grams of 37 percent formaldehyde and 3 grams of para-toluenesulfonic acid as rosin crystallization inhibitors. The reaction mixture is then heated with continuous agitation to about 205°C and held 15 at this temperature 2 to 10 hours.

To form the sizing agent, the first component in the amount of 600 grams and 300 grams of water are placed in a high-speed blender, e.g., a Waring blender. The second component (300 grams), either molten or in the 20 form of solid particles, is-added to the contents of the • blender and agitated for a period of from about-10 -to 60— seconds and preferably about 20 to 30 seconds. Addition of the second component in this manner insures that the second component is finely divided as it contacts the 25 agitated first component.

Potassium hydroxide (60 to 120 grams) in the form of a 50 percent by weight water solution is then added and blended for 5 to 10 seconds. The pH of the solution is then adjusted with sodium hydroxide to a value in the 30 range 9.0 to about 10.0, and sufficient water is added to bring the total solids content of the solution to about 50 percent by weight.

The first neutralization can be done with sodium hydroxide, but if this is done, the second neutralization 35 should be done with potassium hydroxide. 2 08 f 2 Example 2 A first component of a sizing agent s prepared in the same way as that given in Example 1.

To form the second component, 3,000 grams of 5 commercially available tall oil rosin is melted in a cooking vessel. To this rosin is added slowly with moderate agitation 360 grams of fumaric acid. The reaction mixture under continuous moderate agitation is then heated to about 205°C and held at this temperature 2 10 to 14 hours. The hot reaction product is then carefully added to a warm solution of 700 grams rof sodium hydroxide dissolved in 4,032 grams of water. The pH of the final second component solution has a value of about 10.0.

To form the sizing agent, the second component and 15 additional water are mixed in the following proportionss Second Component 115 grams Additional Water 115 grams Total 230 grams — This mixture is then combined vith~190 "grams of ~~ 20 the first "component to form a total of 420 grams of sizing agent.

Example 3 The first and second components of a sizing agent are prepared in the same way as that given in Example 25 1.

To form the sizing agent, the first component in the amount of 600 grams and 300 grams of water are placed in a high-speed blender, e.g., a Waring blender. Three hundred (300) grams of the second component, either 30 molten or in the form of solid particles, is added to the contents of the blender and agitated for a period of from about 10 to 60 seconds and preferably about 20 to 30 seconds. „208123 Potassium hydroxide (6p to 120 grams) in the form of a 50 percent by weight water solution is then added and the solution agitated for a few seconds. The pH of the solution is then adjusted with sodium hydroxide to a value in the range of 9.0 to 10.0 and sufficient water is added to bring the total solids content of the solution to about 50 percent by weight.

Sodium hydroxide can be used for the first neutralization, but if this is done, potassium hydroxide should be used for the second neutralization.

Example 4 In an apparatus such as that illustrated in the drawing, the second component prepared as in Example 1 in the amount of 1,000 parts is formed into a spray by forcing it through an adjustable cone pattern nozzle 2_ (e.g., Nozzle No. 49487650 manufactured by Spray Engineering Co., East Spit Brook Road, Nashua, New Hampshire 03060).- Spray is injected into a tube 3 where it meets a spray 4 of f irst component, - also-prepared as in Example 1, issuing from a full cone center jet nozzle _5. The temperature of the second component is at about 182°C and the nozzle 2 through which it passes is heated by a shroud S_ filled with steam at about 155 psig and at a temperature of about 182°C. The amount of first component is 2,000 parts of a 50 percent by weight solids product. Water from duct 1_ in the amount of 1,000 parts, less the amount of steam coming from the openings in the shroud Q around the nozzle 2 for the second component, is introduced into the apparatus through openings _8 to wash down the walls of the tube 3^ and to prevent a build-up of solids. The reaction product meets a spray £ of 50 percent by weight potassium hydroxide solution containing from 200 to 400 grams of potassium hydroxide introduced into the tube J3 through opening 10 in duct 11. 21 4.Q& 122 The resulting solution JJ2 is then pumped to a storage tank not shown by a pump 1_3 through duct where the pH value is adjusted to from 9.0 to about 10.0 with either KOH or NaOH.

The two nozzles 2 and 5 in the drawing are shown in a configuration such that the two streams of droplets, i.e., sprays and ^ of the second component and first component move concurrently. Other arrangements of the nozzles 2 and 5 may be used including one wherein the nozzles are placed horizontally on a diameter of the tube 2 so that the streams of droplets are directly opposed to each other.

The drawing shows water being run down the inside of the pipe to prevent a build-up of solids. An alternate methpd would be to have a series of water sprays arranged' around the inside periphery of the pipe. " 208123 Example 5 To test the sizing agents by the process of this invention, samples of the products of Examples 1,2 and 3 are treated as follows. The sizing agents are mixed with 5 papermaker's alum in bleached hardwood kraft to compare their performance. Handsheets are made using 5.7 grams of fiber diluted in water to a 1.0 percent by weight slurry. The fiber and water are blended in a Waring blender for about one minute and then the sizing agents 10 in the amount of 10 pounds per ton of fiber are added arid mixed for about 45 seconds. The alum is then added in a ratio of 15 pounds per ton of fiber.

The slurries are then diluted further with water to a fiber solids content of about 0.1 percent based on 15 the weight of the slurry. Sheets are then formed with a Williams Handsheet Former from slurries made with the sizing agents exhibited in the examples. The sheets are placed between two blotters and then dried in a hot press having a temperature of about -110°C and -exerting -a-- - «->■;• i 20 pressure of about 50 pounds per square inch. The sheets are then conditioned for 24 hours at 50 percent relative humidity and 22°C and tested by the TAPPI Hot Ink Float Test.

The ink float test which is used to compare the 25 effectiveness of various sizing agents uses an acid ink of the following composition: 1,000 ml distilled water g Gallic acid 7.5 g FeS04 1.0 g Tartaric acid 1.0 g Sodium benzoate 3.5 g Aniline Blue 50.9 g Formic Acid „ 208123 In the ink float test, squares of paper of a given size are placed on the surface of the liquid ink, and the time is recorded in seconds for 50 percent of the surface to be colored by the ink. In general, the larger the 5 number of seconds recorded for a given run, the more effective is the sizing agent employed in that run.

The results obtained are shown in Table I. Each set of experiments is performed in one day with the same fiber and the same type of water. Control results will 10 vary from day to day depending on the fiber used, the quality of the water, and possibly other factors. „ 208123 Table I Ink Float Test on Sizing Agents Ten Pounds Sizing per Ton of Paper (Second Component Finally Divided) Run No.

Description of Run Method Used to Prepare Sizing Agent Ink Float Test Seconds 1 New method » Control As in Example 1 .

—Second component blended for 20 seconds. Second component added as solid particles. 924 2 Old method a shown in Example 2 612 3 Same as Run 1 New method 1 r 284 4 Same as Run 2 Control - Old method 888 Same as Run 1 New method 1 , 284 6 New method As in Example 1. Second component added as molten product at 205°C 1,236 7 Old method Control as in Example 2 708 8 New method As in Example 3 1/666 9 Old method Control as in Example 2 976 Old method Control as in Example except saponfication done with KOH 2 960 11 New method As in Example 1.

Second component blended for 30 seconds KOH blended for 30 seconds. • 795 12 Old method Control as in Example 2 480 # 203123 The averages of the tests of Table I are as follows: Neither Component Finely Divided (Old method): 771 seconds; Second Component Finely Divided (New method): 1,206 seconds.

This shows an improvement in the new method over the old method of 1,206-771 ?71 x 100% = 56% The values for ink float tests on the controls (V reported in Table I are generally higher than numbers obtained in previous work. This is attributed to the following reasons: (a) the second component is saponified with OH rather than with NaOH; ; (b) a small amount of NaOH is added to the sizing agent after the addition of the second component, and (c) a higher grade of tall oil rosin is being used to react with fumaric acid in the preparation of the second component.

Example 6 - - ~:^20 To test the sizing agents produced by the- process of this invention wherein both first and second components are finely divided, samples of products prepared as in Example 4 are tested with the Ink Float Test.

Handsheet preparation and ink float procedures employed 25 are substantially identical to those described in Example 5. The results obtained are shown in Table II. As before, each set of experiments is performed in one day with the same fiber and the same type of water. Control results will vary from day to day depending on the 30 handsheet size, fiber used, the quality of the water, and , possibly other factors. » 208123 Table II Ink Float Tests on Sizing Agents Ten Pounds Sizing per Ton of Paper Both Components Finely Divided Run No.

Description of Run Method Used to Ink Prepare Sizing Agent Float Test (second s) J • • 1 New method As in Example 4. Rosin is 12% fdrtified with fumaric acid 530 > 2 Control Old method as shown in Example 2. Rosin is 12% fortified with fumaric acid 360 3 Same as Run 1 New method 558 - 4 Same as Run 2 Control - Old method 376 _ Same as Run 1 New method 552 -**■» 1»«.T • . - — . 6 Same as Run 2, ^Control - old method - - - .379 7 New method As in Example 4. Rosin is 6% fort ified"'witli fumaric acid 384 Same as Run 2 Control - Old method 386 The averages of the first six runs in Table II are as follows: Neither Component Finely Divided (Old method): 372 seconds; Both Components Finely Divided (New Method): 547 seconds.

This shows an improvement in the new method over the old method of 547-372 „ mna _ ai*. 272 lUUt - 4/? Runs 7 and 8 in Table II demonstrate that a sizing composition prepared in accordance with the present 208123 invention is about as effective a sizing agent as a similar sizing agent prepared in conventional manner using twice as much of the rosin-modifying fumaric acid material.

Claims (52)

1. 28

   208123

   WHAT //WE CLAIM Uif.

   ■ 1. A process for preparing a sizing composition

   J having improved sizing characteristics, which process

   :v comprises combining

   A) a first component comprising a material which 5 provides both ammonia and ammonium salt when combined with the other sizing composition components, said ammonia-ammonium salt-providing material being selected from the group consisting of ammonia or precursor thereof; ammonium salts or precursor thereof; the 10 reaction product of urea and at least one Lewis acid selected from sulfuryl chloride, chlorosulfonic acid, thionyl chloride, benzenesulfonyl chloride, benzenesulfonic acid, ortho-toluenesulfonic acid, para-toluenesulfonic acid, ortho-toluenesulfonyl 15 chloride, and para-toluenesulfonyl chloride; and mixtures of these materials; and

   B) a second component comprising a saponified, partly saponified or unsaponified rosin which is modified with an organic acidic material selected from

   20 a,3-unsaturated aliphatic carboxylic acids containing from 3 to 10 carbon atoms, anhydrides thereof, and mixtures of said acids and anhydrides;

   said combining of said first component and said second component being effected by forming sprays of said 25 first component and said second component and allowing said sprays to contact each other to thereby provide a sizing composition or precursor thereof, which sizing composition or precursor thereof comprises sizing-effective amounts of said modified rosin, and sizing 30 enhancing amounts of said ammonia and ammonium salt, the amount of said modified rosin, ammonia and ammonium salt being sufficient to provide a sizing composition with a total acidity of at least 1,000 parts per million.

   208123

   29
2. 2. The process of claim 1 wherein said second component is formed into fine particles having an average diameter of from 10 to 1000 microns.
3. 3. The process of claim 1 wherein said first and second components are formed into particles havinq an average diameter of from io to 200 microns.
4. 4. The process of claim 1 wherein said first and second components are converted into sprays by forcing said components through spray nozzles and the sprays are allowed to contact in a suitable container.
5. 5. The process of claim 1 or 4 wherein the rosin is modified with an organic acidic'material selected from the group consisting of maleic acid, maleic anhydride, fumaric acid, and their mixtures.
6. 6. _ The process of claim 5 wherein the ammonium salt of the sizing composition is the salt of a salt-forming acid selected from the group consisting of sulfamic, acid, phosphoric acid, oxalic acid, methane-sulfonic acid, trichloroacetic acid, nitric acidl,

   sulfuric acid, hydrochloric acid, stearic acid and acetic acid.
7. 7. The process of claim 6 wherein said sizing composition is prepared having 3 to 30 percent ammonia, from 4 to 72 percent ammonium salt and from 93 to 25 percent rosin plus organic acidic material, based on the total weight of the ammonia, the ammonium salt and the rosin plus organic acidic material on a dry basis, and using an ammonium salt to ammonia ratio greater than 1 to 1.
8. 8. The process of claim 7 wherein the first component contains ammonia, the rosin is modified with from 5 to 30 percent by weight of the rosin of the organic acidic material and is at least partially saponified; the ammonium salt of the sizing composition ,<

   .fii*"'"

   is produced in situ after combination of the^f-rrst:and

   W

   i

   218123

   30

   second components as the reaction product of the ammonia and the salt-forming acid, and the composition is an aqueous mixture.
9. 9. The process of claim 1 wherein the ammonia of the sizing composition is provided in situ by reaction between the rosin, the rosin-modifying organic acidic material, and the ammonium salt; and the rosin is at least partially saponified.
10. 10. The process of claim 9 wherein said sizing composition is prepared having from 4 to 75 percent ammonium salt and from 96 to 25 percent rosin plus modifying organic acidic material based on the total weight of the ammonium salt and the rosin plus modifying organic acidic material on a dry basis.
11. 11. The process of claim 10 wherein said rosin is modified with from 5 to 30 percent by weight of the rosin of said organic acidic material; and the composition is an aqueous mixture.
12. 12. The process of claim 5 wherein the first component contains ammonia and the ammonium salt of the sizing composition is provided in situ by reaction between the rosin, the organic acidic material, and the ammonia after combination of the first and second components.
13. 13. The process of claim 12 wherein the sizing composition is prepared having from 10 to 75 percent ammonia and from 90 to 25 percent of rosin plus modifying organic acidic material based on the total weight of the ammonia and the rosin plus modifying organic acidic material on a dry basis.
14. 14. The process of claim 13 wherein the rosin is modified with from 5 to 30 percent by weight of the rosin of the organic acidic material and the composition is an aqueous mixture.

    % (»8123

    31
15. 15. The process of claim 12 wherein the rosin is at least partially saponified.
16. 16. The process of claim 15 wherein the sizing composition contains from 4 to 60 percent ammonia and from 96 to 40 percent rosin plus modifying organic acidic material, based on the total weight of the 5 ammonia and the rosin plus modifying organic acidic material on a dry basis.
17. 17. The process of claim 16 wherein the rosin is modified with from 9 to 30 percent by weight of the rosin of the organic acidic material and the composition is an aqueous mixture.
18. 18. The process of claim 5 wherein the rosin is tall oil -rosin and is at least partially saponified.
19. 19. The process of claim 18 wherein said rosin is modified 'with from 5 to 50 percent by weight of the rosin of said organic acidic material.
20. 20- The process of claim 5 wherein said first composition component comprises, from 25 to 85 weight percent and said second composition component comprises from 75 to 15 weight percent of 5 their mixture on a dry weight basis.
21. 21. The process of claim 20 wherein the first component contains a urea-Lewis acid reaction product and wherein the Lewis acid reacted with the urea comprises from 0.2 to 8 percent by weight of the urea.
22. 22. The process of claim 21 wherein the composition is an aqueous mixture.
23. 23. The process of claim 22 wherein the composition contains at least 25 weight percent water.
24. 24. The process of claim 23 wherein the Lewis acid is selected from para-toluenesulfonic acid and para-toluenesulfonyl chloride.

    20812

    32
25. 25. The process of claim 23 wherein ammonia is present in the composition in an amount sufficient to provide a pH of 6.6 to 10.
26. 26. The process of claim 23 wherein ammonium salt is added to the composition to provide a weight ratio of ammonium salt to the urea of from 4 to 1 to 1

    to 2.
27. 27. The process of claim 26 wherein the added ammonium salt is ammonium sulfate.
28. 28. The process of claim 27 wherein the Lewis acid is para-toluenesulfonic acid.
29. 29. The process of claim 23 wherein said sizing composition contains 3 to 30 percent ammonia, from

    4 to 72 percent ammonium salt and from 93 to 25 percent rosin plus modifying organic acidic material, based on the total weight of the ammonia, the ammonium salt and the rosin plus modifying organic acidic material on a dry basis, and wherein the composition is prepared using an ammonium salt to ammonia ratio greater than 1 to 1.
30. 30. The process" of claim 29 wherein the ammonium-salt comprises ammonium salt added to the composition as ammonium salt.
31. ratio of ammonium salt to urea of from 4 to 1 to 1 to 2.
32. 32. The process of claim 31 wherein the Lewis acid is para-toluenesulfonic acid.
33. 33. The process of claim 29 wherein the Lewis acid is para-toluenesulfonic acid.
34. 34. A sizing composition prepared in accordance with the process of claim.. 1, 2, or 4.
35. 35. A sizing composition prepared in accordance with the process of claim 8.

    31. The process of claim 30 wherein the added ammonium salt is ammonium sulfate and is used in weight

    2'*8183

    33
36. 36. A sizing composition prepared in accordance with the process of claim 11.
37. 37. A sizing composition prepared in accordance with the process of claim 17.
38. 38. A sizing composition prepared in accordance with the process of claim 19.
39. 39. A sizing composition prepared in accordance with the process of claim 21.
40. 40. A sizing composition prepared in accordance with the process of claim 28.

    K
41. 41. Cellulosic products sized with from 0.05

    to 4 percent by dry weight of the cellulosic product fibers of a sizing composition produced by the process of claim 1.
42. 42. The cellulosic product of claim 41 which is paper and wherein the rosin is modified with an organic acidic material selected from the group consisting of maleic acid, maleic anhydride, fumaric acid, and their

    5 mixtures.
43. 43. The paper of claim 42 wherein the rosin is tall oil rosin and is at least partially saponified.
44. 44. The paper o£ claim 43 wherein said rosin is modified with from 5 to 30 percent by weight of the rosin of said organic acidic material.
45. 45. Paper sized with from 0.05 to 4 percent by dry weight of the paper fibers of a sizing composition produced by the process of claim 21.
46. 46. A process for preparing a sizing composition having improved sizing characteristics, which process comprises combining:

    A) a first component comprising a material which 5 provides both ammonia and ammonium salt when combined with the other sizing compositions components, said ammonia-ammonium salt-providing material be9Bp^5eTe^Ee3 —

    2H8123

    34

    thereof? ammonium salts or precursor thereof; the reaction product of urea and at least one Lewis acid selected from sulfuryl chloride, chlorosulfonic acid, thionyl chloride, benzenesulfonyl chloride,

    benzenesulfonic acid, ortho-toluenesulfonic acid, para-toluenesulfonic acid, ortho-toluenesulfonyl chloride, and para-toluenesulfonyl chloride; and mixtures of these materials; and

    B) a second component comprising a saponified, partly saponified or unsaponified rosin which is modified with an organic acidic material selected from o ,0-unsaturated aliphatic carboxylic acids containing from 3 to 10 carbon atoms, anhydrides thereof, and mixtures of said acids and anhydrides;

    said combining of said first component and said second component being effected while said second component is in finely divided form and for a period of time up to 60 seconds to thereby provide a sizing composition or precursor thereof, which sizing composition or precursor thereof comprises sizing-effective amounts of said modified rosin, and sizing-enhancing amounts of said ammonia and ammonium salt, the amount of said modified rosin, ammonia and ammonium salt being sufficient to provide a sizing composition with a total acidity of at least 1,0 00 parts per million.

    208123

    35
47. 47. The process of claim 46 wherein said second component is formed into fine particles as said second component is added to said first component while said first component is subjected to high shear agitation sufficient to form second component particles having an average diameter of from 10 to 1000 microns.
48. 48. The process of claim 46 wherein said first component is also finely divided into fine particles while said first and second components are combined, both first and second component particles having an average diameter of from 10 to 200 microns.
49. 49. The process of claim 46, 47 or 48 wherein the period of time is from 10 to 60 seconds. ,
50. 50.* The process of claim 46, 47 or 48 wherein the period of time is from 20 to 30 seconds.
51. 51.' The process of claim 46, 47 or 48 wherein at the end of said period of time the combined first and second components.are then contacted with an aqueous solution of one or both of potassium hydroxide and sodium hydroxide.
52. 52. The process of claim 51 wherein the combined first and second components are -contacted with-an aqueous solution of potassium hydroxide arid then with an aqueous solution of sodium hydroxide.

    DATED THIS OF'^^U-®^

    A. J. PARK & SON PER

    AGENTS FOR THE APPLICANTS