KR20180013942A - From the novel crosslinking agent, a high-efficiency wet strength resin - Google Patents

Abstract

Strength resins and their preparation and use. Strength resins may contain partially crosslinked polyamines with bridging moieties and have azetidinium ions. The bridging moiety may be derived from a functionally symmetrical cross-linking agent. Functionally symmetrical cross-linking agents may include diisocyanate, 1,3-dialkyldiazetidine-2,4-dione, dianhydride, diacyl halide, dienone, dialkyl halide, or any mixture thereof.

Description

From the novel crosslinking agent, a high-efficiency wet strength resin

The disclosed embodiments generally relate to strength resins. More specifically, the embodiment can comprise a partially crosslinked polyamine with a bridging moiety and is a strength resin having an azetidinium ion, wherein the bridging moiety can be derived from a functionally symmetrical cross-linker , A strength resin, and a method of making and using the same.

Paper is a sheet material containing small, discrete fibers interconnected. Fibers are generally formed from sheets of dilute water or slurry in a sheet on a splint screen. Even if synthetic fibers are sometimes used, paper is typically made from cellulose fibers. Paper products made from untreated cellulose fibers lose their strength rapidly when they become wet, i. E. They have very little "wet strength ". The wet strength of a typical paper is only about 5% of its dry strength. The wet strength of a paper is defined as the resistance of the paper to rupture or disintegration when wetted with water. See U.S. Patent No. 5,585,456. To overcome these drawbacks, various methods of treating paper products have been used.

The wet strength resin applied to the paper is either a "permanent" type or a "transient" type, which is defined by how long the paper retains its wet strength after immersion in water. While wet strength maintenance is a desirable feature in packaging materials, paper products with these characteristics exhibit processing problems because they are only degradable under undesirable harsh conditions. Some resins impart temporary wet strength and are suitable for hygienic or disposable paper applications; These resins often suffer from one or more drawbacks. For example, the wet strength of a resin is generally low (about one half of that achievable with a permanent-type resin), the resin can easily be attacked by fungi and mucus, and / . ≪ / RTI >

Conventional resins, which can provide a permanent wet strength to the paper, typically comprise a polyamidoamine polymer such as A , epichlorohydrin ( B ) (" epi "). < / RTI >

Conventional resin synthesis utilizes bifunctional properties of epichlorohydrin to utilize epoxies and chlorine groups for both the cross-linking and the production of the quaternary nitrogen moieties. In these conventional resins, the asymmetric functional group of the epichlorohydrin is converted to a secondary amine of its epoxy group, followed by intermolecular (bridging) with another polyamidoamine molecule in the molecule which is cyclized to produce an azetidinium functional group The reaction with the suspending chlorohydrin moiety leads to ring opening. Thus, the first step of the epi B and polyamidoamine prepolymer A reaction occurs by opening the epoxy group by the secondary amine group of the prepolymer skeleton at a relatively low temperature. A novel functionalized polymer C with a chlorohydrin repeating group is produced and the process typically does not result in a significant change in the prepolymer molecular weight.

The second step involves two competing reactions of the suspending chlorohydrin group: 1) intramolecular cyclization to produce a cationic azetidinium chloride functional group where no increase in molecular weight is observed; And 2) an intermolecular alkylation reaction to crosslink the polymer, which significantly increases its molecular weight. The results of both reactions are illustrated in PAE-epichlorohydrin resin structure D. Indeed, the alkylation, intramolecular cyclization and cross-linking reactions of epichlorohydrin occur simultaneously, but at different rates.

The finished wet strength polymer product, along with a significant amount of quaternary azetidinium chloride functionality, can be obtained by reacting a small amount of residual suspending chlorohydrin, as illustrated in Structure D , and a 3-carbon bridged group having a 2- . The product may also contain significant amounts of epi chlorohydrine hydrolysis product 1,3-DCP, and 3-CPD.

In the above conventional methods, the relative rates of the three main reactions, namely, the formation of hanging chlorohydrin (ring opening), cyclization (cationization) to azetidinium ion group, and crosslinking (intermolecular alkylation) About 140: 4: 1, respectively. Thus, the suspending chlorohydrin group forms very rapidly from the ring opening reaction of the epichlorohydrin epoxide and the secondary amine in the prepolymer. The first step is performed at a low temperature (for example, about 25 캜 to 30 캜).

In the second step, the chlorohydrin group cyclizes relatively slowly to form a cationic azetidinium group. Even more slowly, crosslinking occurs, for example, by: 1) reacting a tertiary amine of the chlorohydrin group, for example, with a moiety secondary amine and / or 2) And intermolecular alkylation of tertiary amines.

In order to maintain practical utility over the minimum reaction cycle time, conventional manufacturing processes typically require that the reaction mixture be heated to increase the reaction rate, for example, from about 60 ° C to about 70 ° C. In general, the reaction is also performed at a high solids content to maximize reactor processing and provides a wet strength resin finished in the highest solids possible to minimize shipping costs. Higher concentrations prefer a slower, intermolecular reaction. Under these high temperature and high concentration conditions, the rate of reaction between intramolecular cyclization and crosslinking becomes competitive. Thus, one problem encountered in conventional manufacturing processes is that the rate at which the rate of crosslinking is desired is fast enough that the endpoint (molecular weight) is achieved at the cost of azetidinium ion group formation. If the reaction continues to exceed the desired endpoint to produce higher levels of azetidinium groups, the reaction mixture will similarly gel and form a solid mass.

Since both azetidinium group content and high molecular weight are useful for the maximum wet strength efficiency of the PAE resin, azetidinium group formation and crosslinking is preferably maximized without providing a product that gels during the gelation or storage of the product. Coupled with the requirement for a high degree of solids to minimize transport costs, these conditions limit aspects of the formation of higher efficiency wet strength resin products.

Thus, there is a need for improved strength resins, for example, imparting adequate levels of wet strength to paper products, and methods of making and using the same.

summary

Strength resins and methods of making and using the same are provided. In at least one example, the strength resin may comprise a partially crosslinked polyamine with a bridging moiety and has an azetidinium ion. The bridging moiety may be derived from a functionally symmetrical cross-linking agent. The functionally symmetrical cross-linking agent can be, or can be, a diisocyanate, a 1,3-dialkyldiazetidine-2,4-dione, an anhydride, a diacyl halide, a dienone, a dialkyl halide, can do.

In at least one example, the method of making a strength resin may include the reaction of a polyamine and a functionally symmetric cross-linker to produce a partially cross-linked polyamine. The functionally symmetrical cross-linking agent can be, or can be, a diisocyanate, a 1,3-dialkyldiazetidine-2,4-dione, an anhydride, a diacyl halide, a dienone, a dialkyl halide, can do. Partially crosslinked polyamines can be reacted with epihalohydrin to produce strength resins with azetidinium ions.

In at least one example, the method of reinforcing the paper may include contacting the strength resin with the fibers. The strength resin may be a partially crosslinked polyamine with a bridging moiety, or may comprise the above and has an azetidinium ion. The bridging moiety may be derived from a functionally symmetrical cross-linking agent. A functionally symmetrical cross-liner can be a diisocyanate, a 1,3-dialkyldiazetidine-2,4-dione, an anhydride, a diacyl halide, a dienone, a dialkyl halide, Or mixtures thereof.

details

A strength resin, for example, a wet strength resin, a method for producing a strength resin, and a paper treatment method for imparting strength using a strength resin are provided. The use of functionalally symmetrical ("symmetrical") crosslinking agents and, optionally, monofunctional modifiers, and functionalization of symmetrical crosslinkers and epihalohydrins from reaction of epihalohydrins, for example epichlorohydrin and partially crosslinked polyamines, There is provided a novel strength resin, for example a wet strength resin, with improved properties and / or improved flexibility in the separation of the reaction of the polyamine into a separate step, its synthesis. In addition to providing generally improved wet tensile development beyond the current state, the products and methods can provide higher azetidinium ion content, an additional degree of reactive functionalization, maximized molecular weight, and / or good storage stability have.

The polyamine crosslinking differs from the " cationization "process of halohydrin-functionalization and cyclization, which is characteristic of providing substantial flexibility in tailoring cationic functionality, molecular weight, and / or other resin properties. The functionally symmetric crosslinking agent and optional monofunctional modifier used to effect crosslinking and functionalization of the polyamine may differ from the reagents used to impart cationic charge to the resin. Specifically, the reaction of a functionally symmetric cross-linking agent with a polyamine may be distinct from the reaction of an epihalohydrin with a partially cross-linked polyamine. For example, a functionally symmetric (or simply "symmetric") crosslinking agent can be used in the first step, which can provide substantial control over the crosslinking structure and properties of a partially crosslinked prepolymer such as a polyamine or polyamidoamine prepolymer . The step of imparting a cationic charge to the resin, the "cationization" process, may utilize any epihalohydrin, such as epichlorohydrin, to produce an azetidinium ion functional group.

The method of making the strength resins can also reduce the amount of epichlorohydrin byproducts when compared to the amounts commonly found in conventional polyamidoamine-epichlorohydrin strength resins that are not made by the process. For example, the strength resins may be selected from 1,3-dichloro-2-propanol (1,3-DCP or "DCP") and 3-chloropropane- 2-diol (3-CPD or "CPD "; also MCPD for monochloropropanediol).

In some instances, a method of making a strength resin, e. G., A wet strength resin, may include the reaction of a polyamine, which may be referred to herein as a polyamine prepolymer, with a functionally symmetrical cross-linker to produce a partially cross- have. As such, the polyamine may be partially crosslinked with a bridging moiety, and the bridging moiety may be derived from a functionally symmetrical crosslinking agent. The epihalohydrin may be added to the partially cross-linked polyamine to produce the halohydrin-functionalized polymer. The halohydrin-functionalized polymer may be cyclized to form a resin having an azetidinium moiety. As such, the strength resin may or may not include an azetidium ion or a moiety, which may or may not be a partially cross-linked polyamine with a bridging moiety.

If desired, the process may further comprise the reaction of the polyamine with a deficiency of a single functional modifier comprising one secondary amine-reactive moiety. If the polyamine is reacted with a deficiency of a monofunctional modifier, the reaction may occur before, during, or after the polyamine is reacted with the symmetric crosslinker, or in different combinations of these times.

In one example, the polyamine may have the structure:

Wherein R may be alkyl, hydroxyalkyl, amine, amide, aryl, heteroaryl or cycloalkyl. In structure P , w may be an integer from 1 to about 10,000. As provided in the definition section, the R group such as "alkyl" or "hydroxyalkyl" is intended to provide a convenient description to which conventional rules of chemical valence apply; Thus, R of structure P may be described as an alkyl or hydroxyalkyl, which is intended to reflect what the "R" group may be described as being divalent and alternatively alkylene or hydroxyalkylene.

The most widely used and most effective wet strength resin products are generally derived from polyamidoamine (PAA) prepolymers reacted with epichlorohydrin to form the so-called polyamidoamine-epichlorohydrin (PAE) resin. Thus, where the polyamine is or is a polyamidoamine prepolymer, the resin is a polyamidoamine-based system without limitation, but is applicable to any amine-containing polymer (polyamine) such as structure P and other amine-containing polymers Is intended.

Epichlorohydrin is a difunctional compound with different, and therefore "asymmetric", chemical, epoxy and chlorine groups. The asymmetric functional group allows ring opening when the epichlorohydrin is reacted with an epoxy group having a secondary amine, followed by a suspending chlorohydrin moiety used both: 1) to form a cationic azetidinium functional group Intramolecular cyclization; Or 2) intermolecular crosslinking of the polymer to increase the molecular weight. The epichlorohydrin resin structure D illustrates the results of both reactions in the polyamidoamine-epichlorohydrin (PAE) resin.

This disclosure is based on the discovery that increased levels of cationic charge (greater charge density), additional functional groups, optimized or maximized molecular weight, higher solids content, and / or lower levels of DCP and CPD from improved azetidinium ion content Concentration, a formulation and process for producing a strength resin, for example, a wet strength resin. In one aspect, the disclosed method separates resin synthesis into two distinct and controllable steps. First, a cross-linked prepolymer of intermediate molecular weight prepared by the reaction of a functionally symmetrical cross-linking agent with a polyamine prepolymer is prepared. Asymmetric Crosslinking Agent Unlike the function of epichlorohydrin, the symmetrical cross-linker of the present disclosure uses the same moiety to react with both prepolymer secondary amine groups to effect crosslinking. If desired, the monofunctional groups may be used before, after, or during the crosslinking step to impart additional functionality to the prepolymer without crosslinking functionality. The second step utilizes epichlorohydrin to impart a cationic functional group without the need for any crosslinking function, by the use of a reduced amount of epichlorohydrin to maximize azetidinium ion formation in the polymer. This process is in contrast to conventional practice, which is limited by the need to optimize competitive < RTI ID = 0.0 > azetidinium ion < / RTI >

Polyamine Prepolymer

The types of polyamines (polyamine prepolymers) may be used as precursors in the wet strength resins disclosed herein. The polyamine may or may not include primary and / or secondary amine moieties linked to at least one spacer.

By way of example, in one aspect, a polyamine, which may be referred to herein as a polyamine prepolymer, may have the structure:

In the formula R can be, for example, alkyl, hydroxyalkyl, amine, amide, aryl, heteroaryl or cycloalkyl. In structure P , w may be an integer from 1 to about 10,000, 1 to about 5,000, 1 to about 3,000, 1 to about 1,000, 1 to about 100, or 1 to about 10. These "R" groups, such as "alkyl ", are intended to provide a convenient description of a designated group resulting from the formal removal of one or more hydrogen atoms (as needed for a particular group) from the moiety. Thus, in the structure P the term "alkyl" will apply the conventional rules of chemical valence applied, but it is possible, for example, to use two hydrogen atoms from an alkane (two hydrogen atoms from one carbon atom or two different hydrogen atoms from two different carbon atoms Quot; alkanediyl "group formed by the formal removal of one hydrogen atom). Such alkyl groups may, unless otherwise specified, be substituted or unsubstituted groups and / or may be acyclic or cyclic groups and / or may be linear or branched. A "hydroxyalkyl" group includes one or more hydroxyl (OH) moieties that are substituted in "alkyl" as defined.

In this aspect and unless otherwise indicated, R of structure P may be an alkyl moiety that is linear (straight chain) or branched. The moiety R may also be cycloalkyl, i. E., A cyclic hydrocarbon moiety having 1 to about 25 carbon atoms. For example, R can have 1 to 25, 1 to 20, 1 to 15, 1 to 12, 1 to 10, 1 to 8, 1 to 6, or 1 to 4 carbon atoms. Also by way of example, R may have from 2 to 10, from 2 to 8, from 2 to 6, or from 2 to 4 carbon atoms. In a further aspect, R is a C ₁ moiety, a C ₂ moiety, a C ₃ moiety, a C ₄ moiety, a C ₅ moiety, a C ₆ moiety, a C ₇ moiety, a C ₈ moiety, a C ₉ moiety , C ₁₀ moiety, C ₁₁ moiety, C ₁₂ moiety, C ₁₃ moiety, C ₁₄ moiety, C ₁₅ moiety, C ₁₆ moiety, C ₁₇ moiety, C ₁₈ moiety, C ₁₉ moiety , C ₂₀ moiety, C ₂₁ moiety, C ₂₂ moiety, C ₂₃ moiety, C ₂₄ moiety, C ₂₅ moiety, C ₂₆ moiety, C ₂₇ moiety, C ₂₈ moiety, C ₂₉ moiety , C ₃₀ moiety.

In the polyamines having the above exemplified structure P , R can also be a poly-primary amine, such as polyvinylamine and its copolymer. Examples of poly-primary amines that can constitute R in structure P include, but are not limited to, the following structures, as well as copolymers with olefins and other unsaturated moieties wherein n is from 1 to about 25 It can be an integer:

Alternatively, n may be an integer from 1 to about 20, 1 to about 15, 1 to about 12, 1 to about 10, or 1 to about 5. In another aspect, n is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, , 23, 24, or 25.

Suitable polyamines (polyamine prepolymers) for use in the making of the present disclosure include, but are not limited to, diethylenetriamine (DETA), triethylenetetramine (TETA), aminoethylpiperazine, tetraethylenepentamine, Hexamine, N- (2-aminoethyl) piperazine, N, N-bis (2-aminoethyl) -ethylenediamine, diaminoethyltriaminoethylamine, piperazine ethyltriethylenetetramine, Polyalkylene polyamines such as polyethylene polyamines. Also useful for the preparation of polyamines for use in the making of the present disclosure are ethylenediamines, low molecular weight polyamidoamines, polyvinylamines, polyethyleneimines (PEI) and other unsaturated copolymerizable monomers such as vinyl acetate and vinyl alcohols and vinyl amines ≪ / RTI >

According to one aspect of the polyamine prepolymer P , w is in the numerical range corresponding to about 2,000 to about 1,000,000 Mw of the polyamine prepolymer. The Mw molecular weight of the polyamine prepolymer P may also be from about 5,000 to about 750,000, from about 7,500 to about 500,000, from about 10,000 to about 200,000, from about 20,000 to about 150,000, or from about 30,000 to about 100,000.

Polyamidomine Prepolymer

The type of polyamidoamine prepolymer can also be used as a precursor in the wet strength resin according to the present disclosure. The polyamidoamine prepolymer is prepared by reacting a polyalkylene polyamine having at least two primary amine groups and at least one secondary amine group with a dicarboxylic acid in the process of forming a long chain polyamide containing a repeating group as disclosed herein . ≪ / RTI > In one aspect, the polyamidoamine prepolymer may have the structure:

Wherein R ¹ is (CH ₂ ) m and wherein m is 2, 3, 4, or 5; R ² is (CH ₂ ) n wherein n is 2, 3, or 4; w is 1, 2, or 3; and p is a numerical value corresponding to a molecular weight of polyamidoamine prepolymer Mw of about 2,000 to about 1,000,000. The Mw molecular weight may also be from about 5,000 to about 100,000, from about 7,500 to about 80,000, from about 10,000 to about 60,000, from about 20,000 to about 55,000, or from about 30,000 to about 50,000.

In one aspect, the polyamidoamine prepolymer may have the structure:

Wherein R ³ is (CH ₂ ) _q , wherein q ranges from 0 to 40; r is a numerical value corresponding to a molecular weight of polyamidoamine prepolymer Mw of about 2,000 to about 1,000,000. Similarly, the Mw molecular weight may also be from about 5,000 to about 100,000, from about 7,500 to about 80,000, from about 10,000 to about 60,000, from about 20,000 to about 55,000, or from about 30,000 to about 50,000. Thus, in the structure (CH ₂ ) _q , q may also be from 0 to about 40, from 0 to about 35, from 0 to about 30, from 0 to about 25, from 0 to about 20, from 0 to about 15, from 0 to about 12, From about 40, 1 to about 35, 1 to about 30, 1 to about 25, 1 to about 20, 1 to about 15, 1 to about 12, 1 to about 10, 1 to about 8, or 1 to about 6 .

In another aspect, the polyamidoamine prepolymer may have the structure:

Wherein n is from 1 to 8; p is 2 to 5; m is from 0 to 40, and similar molecular weight ranges apply.

As disclosed, suitable polyamidoamines are generally prepared by the reaction of polyamines such as polyalkylene polyamines with dicarboxylic acids (diacids), or their corresponding dicarboxylic acid halides or diesters. Suitable polyamines include the polyamines (polyamine prepolymers) disclosed herein which can be used as precursors for the wet strength resin itself. For example, useful polyamidoamines include ethylenediamine itself, diethylenetriamine (DETA), triethylenetetramine (TETA), aminoethylpiperazine, tetraethylenepentamine, pentaethylenehexamine, N- Ethyl) piperazine, N, N-bis (2-aminoethyl) -ethylenediamine, diaminoethyltriaminoethylamine, piperazine ethyltriethylenetetramine, etc., such as polyethylene polyamines Such as p-toluenesulfonic acid, 3-methylglutaric acid, 3-methylglutaric acid, 3-methylglutaric acid, 3-methylglutaric acid, 3-methylglutaric acid, , 3-dimethylglutaric acid and tricarboxypentane such as 4-carboxypimelic acid; Alicyclic saturated acids such as 1,2-cyclohexanedicarboxylic acid, 1-3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid and 1-3-cyclopentanedicarboxylic acid; Unsaturated aliphatic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, aconitic acid, and hexane-3-disacic acid; Unsaturated alicyclic acids such as? 4-cyclohexenedicarboxylic acid; Aromatic acids such as phthalic acid, isophthalic acid, terephthalic acid, 2,3-naphthalenedicarboxylic acid, benzene-1,4-diacetic acid, and heteroaliphatic acids such as diglycolic acid, thiodiglycolic acid, dithiodiglycolic acid, ≪ / RTI > methyliminodiacetic acid. In general, its related diesters of diacid and the formula RO ₂ C (CH ₂ ) _n CO ₂ R (where n = 1 to 10 and R = H, methyl, or ethyl) and mixtures thereof are preferred. Adipic acid is readily available and often used.

Other suitable polyamines may include JEFFAMINE® polyetheramine, available from Huntsman. JEFFAMINE® polyetheramines contain primary amino groups attached to the ends of the polyether skeleton. The polyether skeleton is based on propylene oxide (PO), ethylene oxide (EO), or mixed EO / PO. Other JEFFAMINE® products may contain different skeletal segments and have been capable of varying the reactivity provided by interfering with the primary amine or via secondary amine functionality. Low molecular weight JEFFAMINES®, such as JEFFAMINE® D-230, as well as higher molecular weight JEFFAMINES®, eg JEFFAMINE® D-2000, may be acceptable.

Symmetry Cross-linking agent

Generally, the secondary amine of the polyamine can be reacted with one or more symmetric crosslinking agents. In one example, the reaction of the secondary amine of the polyamine and the symmetric cross-linker can provide a greater control over the cross-linking process, and an intermediate cross-linked prepolymer having a higher molecular weight than the initiator prepolymer. The viscosity endpoint and thus the molecular weight of the intermediate can be readily pre-determined and controlled, at least in part, by the amount of symmetrical cross-linker used. The cross-linking reaction can proceed to the end point as the cross-linking agent is consumed and can be stopped when the cross-linking agent is consumed. A reduced and measurable amount of secondary amine functionality will remain available for further functionalization.

In the crosslinking step, the polyamine may be reacted with a deficiency of a symmetric crosslinking agent, based on the total amount of secondary amine available for crosslinking, to provide a partially crosslinked polyamine. Thus, a partially crosslinked polyamine has a higher molecular weight than a polyamine, even if it is an intermediate in the process and retains a portion of the secondary amine group present in the polyamine. In a further aspect, the partially crosslinked prepolymer possesses the majority of the secondary amine groups present in the polyamine, since less than 50% of the stoichiometric amount of symmetric crosslinker can be used.

Based on the prepolymer repeat unit having a single secondary amine applied to the reaction and the symmetrical cross-linker with two reactive moieties, the stoichiometric reaction of the prepolymer to the cross-linker requires a 2: 1 molar ratio and in fact, the prepolymer- Of 2: 1 or a higher molar ratio is used. In one aspect, the symmetrical crosslinker to prepolymer molar ratio is greater than 0%, but less than 50%, less than 45%, less than 40%, less than 35%, less than 30%, less than 25%, less than 20% of the stoichiometric ratio of crosslinker to prepolymer %, Less than 15%, less than 10%, less than 5%, less than 4%, less than 3%, less than 2%, less than 1%, less than 0.75%, or less than 0.5%. These values reflect the combined molar amount when using more than one symmetrical cross-linker.

The polyamine may be reacted with a symmetric cross-linker in the presence of water or in the absence of water. In one example, the polyamine can be reacted with a symmetric cross-linking agent in an aqueous medium, such as water or a mixture comprising water. In another example, the polyamine can be reacted with a symmetric cross-linking agent in a non-aqueous medium, such as a non-aqueous solvent or diluent. In another example, the polyamine may be reacted with a symmetric cross-linker in the absence of any other liquid medium, whether aqueous or non-aqueous. Non-aqueous media, such as solvents or diluents, may be non-reactive with polyamines, symmetrical crosslinkers, and / or partially crosslinked polyamines. When a polyamine is reacted with a symmetrical cross-linking agent in the absence of any other liquid medium to produce a partially cross-linked polyamine with a bridging moiety or with a symmetrical cross-linking agent, the partially cross-linked polyamine with a bridging moiety can be any water Or substantially without, or mixed with water.

Examples of symmetrical cross-linkers include, but are not limited to, one or more diisocyanates, one or more 1,3-dialkyldiazetidine-2,4-diones, one or more dianhydrides, one or more diacyl halides, Lt; / RTI > or higher, or any mixture thereof. Other examples of symmetrical crosslinking agents include, but are not limited to, one or more di-acrylate compounds, one or more bis (acrylamide) compounds, one or more di- epoxide compounds, one or more polyazetidinium compounds, Methylene-bis-methacrylamide, one or more poly (alkylene glycol) diglycidyl ether, or any mixture thereof. In at least one example, the symmetrical cross-linker comprises at least one of the following: (1) diisocyanate, 1,3-dialkyldiazetidine-2,4-dione, dianhydride, diacyl halide, dienone, and dialkyl halide And may include at least one of the following: (2) a diacrylate compound, a bis (acrylamide) compound, a di-epoxide compound, a polyazetidinium compound, N, N'-methylene-bis- , And poly (alkylene glycol) diglycidyl ether.

The diisocyanate may be unblocked or blocked. Exemplary unblocked diisocyanates include, but are not limited to, 4,4'-methylene diphenyl diisocyanate (methylene diphenyl diisocyanate, MDI); Toluene-2,4-diisocyanate (toluene diisocyanate, TDI); 1,6-hexane diisocyanate (hexamethylene diisocyanate, HDI); 5-isocyanato-1- (isocyanatomethyl) -1,3,3-trimethyl-cyclohexane (isophorone diisocyanate, IPDI), or any mixture thereof. Exemplary blocked diisocyanates include, but are not limited to, bis-caprolactam-blocked 4,4'-methylenediphenyl diisocyanate; 4,4'-methylene diphenyl diisocyanate bis (2-buanone oxime) adduct, bis- (3,5-dimethylpyrazole) blocked 4,4'-methylene diphenyl diisocyanate, ≪ / RTI > Commercially available blocked diisocyanates include, but are not limited to, TRIXENE BI products such as TRIXENE® BI 7641, 7642, 7674, 7675, 7950, 7951, 7960, 7961, 7963, and 7982 available from Baxenden Chemicals, and Rudolf RUCO-Guard products such as RUCO-Guard XCR, XTN, FX 8011, FX 8021, NET, TIE, and WEB, available from the Group.

Exemplary 1,3-dialkyldiazetidine-2,4-diones include, but are not limited to, 1,3-diazetidine-2,4-dione; 1,3-dimethyl-1,3-diazetidine-2,4-dione; 1,3-diethyl-1,3-diazetidine-2,4-dione; 1,3-diphenyl-1,3-diazetidine-2,4-dione; Or any mixture of these. Exemplary dianhydrides include, but are not limited to, pyromellitic dianhydride; Ethylene glycol bis (trimellitic anhydride); 4,4'-bisphenol A dianhydride, or any mixture thereof. Exemplary diacyl halides include, but are not limited to, oxalyl chloride, oxalyl bromide, succinyl chloride, benzene-1,2-dicarbonyl dichloride, benzene-1,2-dicarbonyl bromide, phthaloyl chloride, or And mixtures of any of these. Exemplary dienones include, but are not limited to, 1,7-octadiene-3,6-dione; Bis (2-propen-1-one) - (1,4-benzene), or any mixture thereof. Exemplary dialkyl halides include, but are not limited to, 1,2-dichloroethane; 1,2-dibromoethane; 1,2-diiodoethane; 1,2-dichloropropane; 1,2-dibromopropane; 1,3-dichloropropane; 1,3-dibromopropane; 1,3-diiodopropane; 1,4-bis (chloromethyl) benzene; 1,4-bis (bromomethyl) benzene, or any mixture thereof.

Other useful symmetrical cross-linkers may include, but are not limited to, any one or more of the following:

식 중 R⁴는 (CH₂)_t이고, 및 여기에서 t는 1, 2, 또는 3임;

Wherein R ⁴ is (CH ₂ ) _t , and wherein t is 1, 2, or 3;

식 중 x는 1 내지 약 100임;

Wherein x is from 1 to about 100;

식 중 y는 1 내지 약 100임;

Y is from 1 to about 100;

식 중 x' + y'는 1 내지 약 100임; 및/또는

X ' + y ' is from 1 to about 100; And / or

식 중 z는 1 내지 약 100임; 이들의 임의의 조합을 포함함.

Wherein z is from 1 to about 100; Includes any combination of these.

Specific examples of the symmetrical crosslinking agent include N, N'-methylene-bis-acrylamide, N, N'-methylene-bis- methacrylamide, poly (ethylene glycol) diglycidyl ether, poly (propylene glycol) diglycidyl Diethers, polyethylene glycol diacrylates, polyazidinium compounds, and any combination thereof.

According to a further aspect, the symmetrical cross-linking agent may be selected from a specific polymer or co-polymer having the type of functional moiety reactive with the secondary amine, i.e., capable of functioning as a symmetrical cross-linker according to the present disclosure, . In one aspect, these polymeric symmetrical cross-linkers may be polymers or copolymers comprising an azetidinium functional group. These polymeric symmetrical cross-linking agents are, for example, azetidinium-functionalized monomers such as 1-isopropyl-3- (methacryloyloxy) -1-methyl azetidinium chloride Q or 1,1- Methacrylates, alkenes, dienes, and the like, and 3-hydroxyazetidinium chloride R (the structures of which are illustrated below) and acrylates, methacrylates, alkenes, dienes, and the like.

The polymeric symmetric cross-linking agent can also be, for example, a copolymer of other azetidinium-functionalized monomers such as the compounds S , T , or U as shown here and the acrylates, methacrylates, alkenes, dienes, Or may include the above.

In this aspect, the symmetrical cross-linking agent is selected from a copolymer of an azetidinium-functionalized monomer selected from Q , R , S , T , U , and combinations thereof and an acrylate, methacrylate, alkene, or diene. , Wherein the fraction of azetidinium-functionalized monomer for the acrylate, methacrylate, alkene, or diene monomer in the copolymer may be from about 0.1% to about 12% . In a further aspect, the fraction of azetidinium-functionalized monomer for the acrylate, methacrylate, alkene, or diene monomer in the copolymer is from about 0.2% to about 10%, from about 0.2% to about 10%, from about 0.5 %) To about 8%, about 0.75% to about 6%, or about 1% to about 5%. Examples of these types of symmetrical cross-linker polymers and co-polymers can be found in the following references: Y.Bogaert, E. Goethals and E. Schacht, Makromol . Chem . , 182 , 2687-2693 (1981); M. Coskun, H. Erten, K. Demirelli and M. Ahmedzade, Polym . Degrad . Stab. , 69 , 245-249 (2000); And U.S. Patent No. 5,510,004.

According to one aspect, the symmetrical cross-linking agent may be selected from or include at least the azetidinium-functionalized polyamidomaines. That is, the polyamidomaines may have minimal azetidinium functionalities, which are reactive moieties in this type of symmetric crosslinking agent. In this case, the crosslinking function is influenced by the azetidinium moiety, which can react with the secondary amine of the polyamidoamine prepolymer. Polyamidoamines suitable for preparing the azetidinium-functionalized polyamidomines at least include the same general structures and formulas that can be used in the preparation of the resin itself, such as the structures X , Y , and Z exemplified herein. Examples of minimal azetidinium-functionalized polyamidomines suitable for use as symmetrical cross-linkers are illustrated by the following structures:

Wherein p is 2 or more and, q / p ratio is about 10 to about 1000, the structure has a function to cross-linked, and at least two azepin tea pyridinium moiety functionally Jung Sung-hwa a structure example X as a symmetric cross-linking agent . As indicated by the q / p ratio, there is a small fraction of the azetidinium moiety when compared to the acid and amine moieties. Moreover, the polyamidoamine X may also have a structure with a q / p ratio of from about 12 to about 500, from about 14 to about 400, from about 16 to about 300, from about 18 to about 200, or from about 20 to about 100. One type of minimally azetidinium-functionalized polyamidomine is provided, for example, in U.S. Patent No. 6,277,242.

As illustrated by the molar ratio of symmetrical cross-linker to polyamine, for example, PAE prepolymers, generally, relatively small fractions of available secondary amine moieties can be cross-linked to form a branched or partially cross-linked polyamidoamine prepolymer do. In addition to the molar ratios provided herein, for example, the symmetric crosslinker to prepolymer molar ratio may be selected to provide from 0.01% to 5% of the stoichiometric ratio of crosslinker to prepolymer. In a further aspect, the symmetrical cross-linker to prepolymer molar ratio is from 0.1% to 4%, from 0.2% to 3.5%, from 0.3% to 3%, from 0.4% to 2.5%, from 0.5% to 2% of the stoichiometric ratio of cross- 0.6% to 1.5%. These values reflect the combined molar amount when using more than one symmetrical cross-linker.

By way of example, using polyamide-amine prepolymers derived from adipic acid and diethylenetriamine (DETA) as examples and using prepolymer crosslinking with methylene-bis-acrylamide (MBA), partially crosslinked polyamidoamines The prepolymer can be illustrated by the following structure:

The R ^X bridging moiety in the formula has the structure:

The above examples do not reflect the use of any single functional modifier (as above ) in addition to the symmetrical crosslinking agent.

Monofunctional Strain

The secondary amine groups of the polyamine may also be reacted with one or more monofunctional compounds to impart any desired chemical functional group to the prepolymer. The monofunctional compounds may be selected from the group consisting of secondary or primary amines and cationic (to increase cationic charge density), non-cationic (to modulate interaction with non-ionic segments of the cellulosic fibers) Lt; RTI ID = 0.0 > reactive < / RTI > As desired, the polyamine may be reacted with a deficiency of a symmetrical cross-linker and a deficiency of a single functional modifier that may comprise one secondary amine-reactive moiety before, during, or after the reaction step of the polyamine. In addition, the stoichiometric deficit and reaction of the monofunctional modifier can also be performed before, during, or after the reaction with the symmetric crosslinker using any combination of reactions or additions.

For example, in one aspect, the monofunctional modifier is selected from a neutral or cationic acrylate compound, a neutral or cationic acrylamide compound, an acrylonitrile compound, a mono-epoxide compound, or any combination thereof Or may include the above. According to a further aspect, the single functional modifier is selected from the group consisting of alkyl acrylates, acrylamides, alkyl acrylamides, dialkyl acrylamides, acrylonitrile, 2-alkyloxirane, 2- (allyloxyalkyl) oxirane, Acrylate, ω- (acryloyloxy) -alkyltrimethylammonium compound, ω- (acrylamido) -alkyltrimethylammonium compound, and any combination thereof. Examples of monofunctional modifiers are illustrated below.

For example, the single functional modifier may be at least one of the following or may include: methyl acrylate; Alkyl acrylates; Acrylamide; N-methyl acrylamide; N, N-dimethylacrylamide; Acrylonitrile; 2-methyloxirane; 2-ethyloxirane; 2-propyloxirane; 2- (allyloxymethyl) oxirane; 2-hydroxyethyl acrylate; 2- (2-hydroxyethoxy) ethyl acrylate; 2- (acryloyloxy) -N, N, N-trimethylethanaminium; 3- (acryloyloxy) -N, N, N-trimethylpropane-1-aminium; 2-acrylamido-N, N, N-trimethylethanaminium; 3-acrylamido-N, N, N-trimethylpropane-1-aminium; And 1-isopropyl-3- (methacryloyloxy) -1-methyl azetidinium chloride. Depending on the nature of the modifier, the non-reactive moieties to the amines upon reaction of these compounds with secondary or primary amines can impart cationic charge to assist in increasing the cationic charge density, e.g., It is shown that hydrophilic or hydrophobic characteristics can be altered to coordinate interaction with the non-ionic segments of the cellulose fibers, and / or affect other properties of the resultant intermediate cross-linked prepolymer .

The monofunctional modifier may comprise from about 0.0001 mole, about 0.0005 mole, about 0.001 mole, about 0.005 mole, or from about 0.01 mole to about 0.05 mole, from about 0.07 mole, to about 0.1 mole, from about 0.15 mole , Or about 0.2 moles of the polyamine. For example, a single functional modifier can be reacted with a secondary amine group of the polyamine in an amount of from about 0.0001 mole to about 0.1 mole per mole of secondary amine group.

Halohydrin - Functionalized Polymer  And Intramolecular  Cyclization

In general, by separating the reaction of the cross-linking agent and the polyamine from the reaction of the epichlorohydrin with the intermediate cross-linked prepolymer into separate steps, the second reaction step is preferably carried out in the presence of less epichlorohydrin than the conventional method to achieve the desired end point I need a drink. In addition, the second reaction step may be effected under reaction conditions favoring optimized azetidinium group formation during further crosslinking. The asymmetric functional group of the epichlorohydrin is reacted with a relatively easy reaction of the secondary amine and the epoxy group to form the suspending chlorohydrin moiety in the above functionalization, followed by the addition of the suspending chlorohydrin To < / RTI > The latter intramolecular cyclization may utilize heating of the halohydrin-functionalized polymer.

In one aspect, the second reaction step can be carried out using any epihalohydrin, such as epichlorohydrin, epibromohydrin, and epi-iodohydrin, or any combination thereof. For example, epichlorohydrin may be used. In the present disclosure, it is understood that any epihalohydrin can be used in the process when, for example, the epichlorohydrin is listed in the structure or reaction scheme.

By way of example, using crosslinking with the exemplified partially crosslinked polyamidoamine prepolymer and MBA derived from adipic acid and DETA, the epichlorohydrin functionalized product has the following structure, the so-called "halohydrin- Quot; polymer "

As before, these examples do not reflect the use of any single functional modifier in addition to the symmetric cross-linking agent. The reaction of the epihalohydrin, such as epichlorohydrin, can be accomplished by dissolving a halohydrin-functionalized polymer, in this case, a high percentage or residual secondary amine moiety in the chlorohydrin-functionalized polymer production It is tailored.

The formation of the halohydrin-functionalized polymer can be carried out using a range of epichlorohydrin molar ratios. For example, the reaction may be carried out using excess epichlorohydrin. The stoichiometric reaction of the secondary amine group with epichlorohydrin requires a 1: 1 molar ratio of secondary amine to epichlorohydrin. In one aspect, about 0.8 to about 3 moles of epichlorohydrin per mole of secondary amine can be used. Alternatively, about 0.9 to about 2.5 moles of epichlorohydrin per mole of secondary amine, about 1.0 to about 2.0 moles, about 1.1 to about 1.7 moles of epichlorohydrin per mole of secondary amine, about 1.2 Mole to about 1.5 mole, and about 1.25 mole to about 1.45 mole may be used. For example, the moles of moles of epichlorohydrin per mole of secondary amine may be about 0.8, about 0.9, about 1.0, about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, or about 1.6.

The amount of symmetrical cross-linking agent and epihalohydrin may be sufficient to produce a strength resin that can not have a substantially secondary amine group. While the above results may be influenced by the use of the molar amounts and ratios disclosed herein, the resin compositions prepared by this disclosure can not substantially contain secondary amine groups even when molar amounts and ratios other than those quoted are used. By virtue of the absence of a secondary amine group, it is meant that less than 10% of the initial secondary amine remains in the initiating PAE resin prior to crosslinking, functionalization, and cationization reactions. Alternatively, less than 5%, less than 1%, less than 0.5%, less than 0.2%, less than 0.1%, less than 0.01%, less than 0.005%, or less than 0.001% of the initial secondary amine in the initial PAE resin Can remain.

The halohydrin (typically chlorohydrin) -functionalized polymer can be converted into a wet-strength resin by treating the polymer with cyclization conditions to form an azetidinium ion. The functionalized polymer can be heated to form azetidinium ions. In contrast to conventional methods wherein heating induces both crosslinking and cyclization, the crosslinking portion of the process is completed when the cyclization is carried out, thereby allowing for greater process control and more closely tailoring the desired properties of the resulting resin . In contrast to conventional methods, the processes discussed and described herein reduce and / or minimize the formation of the epichlorohydrin by-product 1,3-dichloro-2-propanol (1,3-DCP or "DCP" 3-chloropropane-1,2-diol (3-CPD or "CPD") remaining in the resin can be reduced or minimized.

The concentration of remaining epichlorohydrin 1,3-dichloro-2-propanol (1,3-DCP) in the strength resin with 25% solids (DCP @ 25%) is less than about 15,000 ppm, less than about 14,000 ppm, less than about 12,000 ppm, less than about 11,500 ppm, less than about 11,000 ppm, less than about 10,500 ppm, less than about 10,000 ppm, less than about 8,000 ppm, less than about 6,000 ppm, or less than about 5,000 ppm.

The following resin composition structure Z is prepared by reacting quaternary nitrogen based on the chlorohydrin-functionalized polymer Y shown above , which is applied to conditions sufficient to cyclize the suspending chlorohydrin into the molecule to impart an azetidinium functionality ("Cationization") step for the formation of the reaction product.

In the step of forming the resin composition, the resin composition is produced by applying a halohydrin-functionalized polymer to a cyclization condition sufficient to convert halohydrin groups to form azetidinium ions. At least a portion of the halohydrin group may be cyclized to form an azetidinium ion or moiety. In one example, at least 90% of the halohydrin groups can be cyclized to form an azetidinium ion. Alternatively, at least 95%, at least 97%, at least 98%, at least 98.5%, at least 99%, at least 99.5%, at least 99.7%, at least 99.8%, or at least 99.9% of the halohydrin groups may contain azetidinium ions Lt; / RTI >

An additional step of resin processing can be used, for example, to adjust the solids content of the composition beyond what is described in detail above. For example, the resin composition can be produced by converting the halohydrin-functionalized polymer to an azetidinium functionalized polymer. After this step, the pH polymer composition can be adjusted such that the pH of the resin composition is from about 2 to about 4.5. Alternatively, the pH of the resin can be from about 2.2 to about 4.2, from about 2.5 to about 4, or from about 2.7 to about 3.7. In another example, the pH of the polymer composition is from about 2, about 2.1, about 2.2, about 2.3, about 2.4, about 2.5, about 2.6, or about 2.7 to about 3 , About 3.2, about 3.4, about 3.6, about 2.8, about 4, about 4.2, or about 4.5. The pH adjustment step may also be followed by adjusting the solids content of the composition from about 10% to about 50% to form a strength resin. Alternatively, the solids content of the composition can be adjusted from about 15% to about 40% or from about 20% to about 30% to form the strength resin. In another example, the strength resin may have a solids content of about 25%.

The resulting strength resins may have improved charge densities as compared to conventional resins. For example, the strength resin may have a charge density of from about 2 to about 4 mEq / g of solids. Alternatively, the strength resin may comprise from about 2.25 to about 3.5 mEq / g of solids, from about 2.3 to about 3.35 mEq / g of solids, from about 2.4 to about 3.2 mEq / g of solids, or from about 2.5 to about 3.0 mEq / g charge density.

The resulting strength resin may also have a ratio of azetidinium ion to amine residues in the strength resin, from about 0.4 to about 2.3, as outlined in "Azet". The Azet ratio may also be from about 0.5 to about 1.9, from about 0.6 to about 1.6, or from about 0.7 to about 1.3. In another example, the ratio of the azetidinium ion to the secondary amine moiety in the resin may be from about 0.4 to about 1. The Azet ratio can be measured by quantitative < ¹³ > C NMR by comparison of the methylene carbon of the azetidinium to the methylene of the acid residue in the skeleton.

In another example, the strength resin may have a Mw molecular weight of about 0.02 x 10 ⁶ to about 3.0 x 10 ⁶ . Alternatively, the resin is from about 0.05 × 10 ⁶ to about 2.5 × 10 ^6, approximately 0.1 × 10 ⁶ to about 2.0 × 10 ^6, approximately 0.5 × 10 ⁶ to about 1.5 × 10 ^6, or about 1 × 10 ⁶ to about And may have a Mw molecular weight of 1.0 x 10 < ⁶ >. In another example, the resin may have a Mw molecular weight of from about 0.05 × 10 ⁶ to about 1.7 × 10 ^6. Mw molecular weight is also from about 0.6 × 10 ⁶ to about 1.6 × 10 ^6, approximately 0.7 × 10 ⁶ to about 1.5 × 10 ^6, approximately 0.8 × 10 ⁶ to about 1.3 × 10 ^6, or about 0.9 × 10 ⁶ to about 1.1 × 10 ⁶ can be.

The strength resin may have an azetidinium equivalent of about 1,600 to about 3,800, defined as the degree of polymerization times Azet ratio, or (degree of polymerization) x (Azet). Alternatively, the azetidinium equivalent can be from about 1,800 to about 3,500, or from about 2,000 to about 2,900.

Strength resins can also hold various combinations of the disclosed properties. For example, the strength resin may have a charge density, an Azet ratio, a Mw molecular weight, an azetidinium equivalent, a 1,3-DCP content, a halohydrin group that is cyclized to form an azetidinium ion, At least two, at least three, at least four, or at least five. For example, the strength resin may or may not have at least two, at least three, at least four, or all five of the following characteristic features: (a) from about 2.25 to about 3.5 mEq / g of solids Charge density; (b) the ratio of azetidinium ion to amide in the strength resin is from about 0.7 to about 0.9; (c) a molecular weight Mw of from about 0.05 x 10 ⁶ to about 1.5 x 10 ⁶ ; (d) an azetidinium equivalent of from about 1,800 to about 3,500; And (e) less than about 10,000 ppm 1,3-dichloro-2-propanol (1,3-DCP) content when the solids content is about 25%.

Conventional Wet strength  Compared with resin systems

As described for conventional wet strength resin production, it has been found that in the above conventional processes, three main reactions are carried out: the formation of hanging chlorohydrins (ring opening), cyclization (cationization) to azetidinium ion groups, and crosslinking ) Is approximately 140: 4: 1, respectively, when performed at room temperature. Thus, the suspending chlorohydrin group forms very rapidly from the ring opening reaction of the epichlorohydrin epoxide and the secondary amine in the prepolymer using about 1: 1 molar ratio of epichlorohydrin to the secondary amine. The chlorohydrin group then cyclizes relatively slowly to form the cationic azetidinium group. Even more slowly, cross-linking occurs, for example, by: 1) a tertiary amine of a chlorohydrin group which reacts with, for example, an azetidinium moiety; And / or 2) intermolecular alkylation of the pendant chlorohydrin moiety and the tertiary amine. Thus, in the crosslinking step in the reaction scheme of the reaction, there is substantially no residual secondary amine groups. Crosslinking results in an increase in the molecular weight, which is manifested in an increase in the resin viscosity.

To maintain practical utility for minimum reaction cycle time, the manufacturing process can be performed under high temperature and high concentration conditions, where the rate of reaction between intramolecular cyclization and crosslinking becomes competitive. Thus, one problem encountered in conventional manufacturing processes is that the desired viscosity is such that the cross-linking reaction rate is fast enough to the extent that the end point (molecular weight) is achieved at the cost of azetidinium ion group formation. If the reaction continues beyond the end point as the desired viscosity to produce a higher level of azetidinium groups, the reaction mixture is likely to gel and form a solid mass.

Since both the azetidinium group content and the high molecular weight are useful for the maximum wet strength efficiency of the PAE resin, azetidinium group formation and crosslinking are preferably maximized without providing a product that gels during the gelation or storage of the product. These conditions, coupled with the requirement for a high degree of solids to minimize transport costs, limit aspects of the formation of higher efficiency wet strength resin products.

In contrast, the strength resins and processes discussed and discussed herein address at least in part this problem by providing higher azetidinium ion content, an additional degree of reactive functionalization, increased molecular weight, and very good storage stability. Strength resins provide improved wet tensile development beyond the current state when used in paper, cardboard, tissue and towel applications.

A comparison of wet strength resin properties with standard commercially available wet strength resins is provided in the Examples and Tables. The wet strength resin properties of the resins prepared in accordance with this disclosure were compared and checked with standard commercially available wet strength resin products, including the AMRES® series of resins (Georgia-Pacific) and KYMENE® (Ashland) resins . Both the performance of the resin to impart the wet strength and the properties of the resin itself are compared in the following table. The data illustrate a significant improvement in resin properties (Table 1), such as increased charge density, higher fraction of azetidinium ion to amide residues, higher molecular weight, greater azetidinium equivalent, and lower byproduct contaminants It has been observed in the disclosed resins when compared to conventional resins.

According to another aspect, strength resins are provided for improving the wet strength of paper. The method of making a resin or a resin composition may involve the reaction of a polyamine with a symmetric cross-linker to produce a partially cross-linked polyamine. The epihalohydrin may be added to the partially cross-linked polyamine to produce the halohydrin-functionalized polymer. The halohydrin-functionalized polymer may be cyclized to form a resin having an azetidinium moiety.

When the polyamine (polyamine prepolymer) is selected from polyamidoamine prepolymers, a further aspect of the present disclosure provides a resin for improving the strength of the paper, for example, the wet strength, wherein the resin is derived from a functionally symmetrical cross- Lt; RTI ID = 0.0 > bridging < / RTI > moiety and has an azetidinium ion. The resin or resin composition is prepared by reacting a secondary amine-reactive moiety to provide a partially crosslinked polyamidoamine prepolymer having a plurality of, for example, a plurality of secondary amine groups present in the polyamidoamine prepolymer (PAA) prepolymer having a secondary amine group and a deficiency of a symmetrical crosslinking agent having a secondary amine group. If desired, the polyamidoamine prepolymer may be reacted with a symmetric cross-linking agent and with a deficiency of a single functional modifier that may comprise one secondary amine-reactive moiety before, during, or after the reaction. The partially crosslinked polyamidoamine prepolymer may be reacted with an epihalohydrin to provide a halohydrin-functionalized polymer. The resin composition may be formed by applying a halohydrin-functionalized polymer under conditions sufficient to cyclize at least a portion of the halohydrin groups to form an azetidinium ion.

Any paper reinforced with a strength resin is also an aspect of this disclosure and is provided herein. Moreover, the paper treatment process for imparting wet strength can include treatment of the fibers used to make paper with dry resin solids, wherein the resin is any resin in this disclosure. For example, the process may include treatment of the fibers used to make the paper from about 0.05% to about 2% by weight dry resin solids, based on the dry weight of the fibers of the cationic thermosetting resin or resin composition, The resin or resin composition is prepared according to the present disclosure. The paper treatment process for imparting wet strength can include treatment of the fibers used to make the paper with from about 0.01 wt% to about 2 wt% dry resin solids, based on the dry weight of the fibers of the cationic thermoset resin composition . Alternatively, the process may use from about 0.05 wt% to about 1.8 wt%, from about 0.075 wt% to about 1.6 wt%, or from about 0.1 wt% to about 1.5 wt% dry resin solids, based on the dry weight of the fibers . The fibers may be pulp fibers.

Although each of the resin composition characteristics disclosed herein is described in detail independently of other properties, it is contemplated that any resin composition characteristics may arise with any other resin properties or characteristics in the disclosed resin. By way of example and not limitation, the disclosure of the specification herein includes compositions that can have at least one, at least two, at least three, at least four, or at least five of the following characteristics: a) A charge density of from about 1.0 to about 4.0 mEq / g of solids; b) the ratio of azetidinium ion to amide residue in the resin is from about 0.5 to about 0.9; c) from about 0.05 × 10 ⁶ to about 3.0 × 10 ⁶ molecular weight; d) an azetidinium equivalent of from about 1,800 to about 3,500; And e) 1,3-dichloro-2-propanol (1,3-DCP) content of less than about 10,000 ppm when the solids content is about 25%.

In order to more clearly define the terms used herein, unless defined to the contrary, definitions are applied, for example, by adhering to the conventional rules of chemical valence so that the definition does not limit or enable any claim The following definitions, applicable to one present disclosure, are provided. Where a term is used in this disclosure but is not specifically defined herein, it is to be understood that, unless the definition conflicts with any other disclosure or definition applied herein, or that the claim is intended to encompass any and all claims, Definitions can be applied from the IUPAC overview of Chemical Terminology, 2 ^nd Ed (1997). The definitions or usage provided herein control the extent to which any definition or use provided by any document incorporated herein by reference contradicts the definitions or usage provided herein.

 While compositions and methods are described with reference to "comprising " various components or steps, the compositions and methods may also consist essentially of, or consist of, the various components or steps.

Unless otherwise specified, any carbon-containing group to which the number of carbon atoms is not assigned may be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 carbon atoms, Lt; / RTI > For example, unless otherwise specified, any carbon-containing group may contain from 1 to 30 carbon atoms, from 1 to 25 carbon atoms, from 1 to 20 carbon atoms, from 1 to 15 carbon atoms, from 1 to 10 carbon atoms, Carbon atoms, and the like. Moreover, other identifiers or quantification terms may be used to indicate the presence or absence of a particular substituent, a particular positional chemistry and / or stereochemistry, or the presence of a branched base structure or an absence of a backbone.

When used to describe a group, for example, when referring to a substituted group of a particular group, the term "substituted" is intended to describe any non-hydrogen moiety that formally replaces hydrogen in that group, It is intentional. Applicants, however, have the right to limit the scope of any claim to cite any group, for example, to describe the prior disclosure that the applicant may not know. The group or group may also be referred to herein by equivalent terms such as "non-substituted ", or" unsubstituted ", which refers to the initial group in which the non-hydrogen moiety does not replace hydrogen within the group. "Substituted" includes, but is not limited to, inorganic substituents or organic substituents as specified and as recognized by those skilled in the art.

The term "alkyl group" is a generic term used to denote a group formed by the removal of one or more hydrogen atoms (as needed for a particular group) from an alkane, as used herein. Thus, the term "alkyl group" includes definitions specified by the IUPAC of the monovalent group formed by the formal removal of a hydrogen atom from an alkane, but also includes, for example, as long as the usual rules of chemical valence apply, Includes an "alkanediyl group" formed by the formal removal of two hydrogen atoms from an alkane (two hydrogen atoms from one carbon atom or one hydrogen atom from two different carbon atoms), if allowed. The alkyl group may be a substituted or unsubstituted group and may be a non-cyclic or cyclic group and / or may be linear or branched unless otherwise specified.

The term "cycloalkyl group" is a generic term referring to a group formed by the removal of one or more hydrogen atoms (as needed for a particular group) from a cycloalkane, as used herein. Thus, a "cycloalkyl group" includes the definition specified by the IUPAC of a monovalent group formed by the formal removal of a hydrogen atom from a cycloalkane, but also, for example, as long as the usual rules of chemical valence apply, Quot; cycloalkanediyl group "formed by the formal removal of two hydrogen atoms (two hydrogen atoms from one carbon atom or one hydrogen atom from two different carbon atoms) from an alkane, . The alkyl group may be a substituted or unsubstituted group and may be a non-cyclic or cyclic group and / or may be linear or branched unless otherwise specified. When two hydrogens are formally removed from a cycloalkane to form a "cycloalkyl" group, the two hydrogen atoms may be removed from the same ring carbon, from two different ring carbons, or one ring carbon and one non- Can be formally removed from the carbon atom.

"Aryl group" refers to a group formed by removal of one or more hydrogen atoms from an aromatic compound, specifically, an arene (if necessary for a particular group and at least one of them is an aromatic ring carbon atom). Thus, the term "aryl group" includes monovalent groups formed by the formal removal of hydrogen atoms from arenes, but also includes, for example, formally removing two hydrogen atoms from the arene (at least one of them from an aromatic hydrocarbon ring carbon) And "allendiyl group" Thus, an aromatic compound is a compound containing cyclically bonded hydrocarbons conforming to the Hueckel (4n + 2) rule and containing (4n + 2) pi-electrons, wherein n is an integer from 1 to about 5. Thus, the aromatic compound and thus the "aryl group" may be monocyclic or polycyclic, unless otherwise specified.

"Heteroaryl group" refers to a group formed by removal of one or more hydrogen atoms from a heteroaromatic compound (optionally with a group and at least one of which is an aromatic ring carbon or heteroatom). Thus, one or more hydrogen atoms may be removed from the ring carbon atom and / or from a heteroaromatic ring or ring system heteroatom. Thus, a "heteroaryl" group or moiety is a heteroarylene group, or heteroarylene group, which may be a heteroarylene ring or a cyclic carbon atom, at least one of the heteroarylene compounds being a " Quot; Thus, in the "heteroarylene diyl group", at least one hydrogen is removed from the heteroarene ring or cyclic carbon atom and the other hydrogen atom is, for example, a heteroarylene ring or a ring carbon atom, or a non- Or from any other carbon atom, including ring-based atoms.

An "amide" group or moiety refers to a group formed by removal of one or more hydrogen atoms (as needed for a particular group) from an amide compound, including an organic amide compound. Thus, one or more hydrogen atoms may be removed from the carboxyl group carbon, from the amide nitrogen, from any organic moiety bonded to the carboxyl group carbon or amide nitrogen, or from an organic moiety bonded to the carboxyl group carbon, Can be removed from the tee. Often, for example, when an amide group links an amine in a polyamine, the "amide" group or moiety may be attached to each of the two organic groups, one attached to the carboxyl group, and the amide nitrogen, Occurs. The term may be used in any amide moiety, whether an amide or an aliphatic or aromatic organic group.

The use of various substituted analogs or formal derivatives of any of these groups may also be disclosed, in which case analogs or formal derivatives, unless otherwise indicated, are the number of substituents or specific positional chemistries. For example, the term "hydroxyalkyl" refers to a group formed by the formal removal of one or more hydrogen atoms (as needed for a particular group) from the alkyl portion of a hydroxy-substituted alkane. The hydroxy-substituted alkane may comprise one or more hydroxy substituents. Thus, "hydroxyalkyl" groups may be substituted by, for example, two hydrogen atoms from a "hydroxyalkyl" alkane, as long as the usual rules of chemical valence apply, Substituted "alkanediyl" group formed by the formal removal of a hydrogen atom or one hydrogen atom from two different carbon atoms. As indicated for an alkyl group, an alkyl group may be a substituted or unsubstituted group and / or may be a non-cyclic or cyclic group and / or may be linear or branched, unless otherwise specified.

The synthesis of standard PAE wet strength resins using epichlorohydrin and adipic acid and DETA is shown in Scheme 1. A resin according to one or more embodiments discussed and described herein using a symmetrical cross-linker, methylene bis-acrylamide (MBA), is shown in Scheme 2.

1, intermediate cross-linked prepolymer, MBA = methylene-bis-acrylamide, step # 2, epichlorohydrin, 1.35 mol / second amine, intramolecular cyclic azetidine Dimium ions, suspended chlorohydrin

Scheme 2

Wet strength In the house Azetidinium  Rain Azet  Rain) ¹³ C NMR determination

Azetidinium ratio, or "Azet" ratio is the ratio of the total number of polymer segments containing azetidinium ions to the polymer segment. The single polymer segment is defined as condensed moieties derived from one discrete molecule (e. G. Adipic acid) and one triamine molecule (e. G., Diethylenetriamine or DETA) illustrated below.

The azetidinium ion ratio is determined by quantitative (reverse gated heteronuclear decoupled) ¹³ C NMR spectroscopy, using a relaxation time of 22.5 seconds, a spectral width of 15,000 Hz (240 ppm), and 320 to 1024 scans . The measurement was carried out by incorporation of the methylene peak in the azetidinium ion and the internal carbon of the adipic acid portion of the polymer. The adipic acid moiety is assigned so as to be the total number of polymer segments. Thus, when the polymer is prepared using adipic acid, the azetidinium ratio is determined according to the formula:

The azetidinium ion ratio (Azet ratio) = A (azet) / A (adip)

A (azet) is the integral area of methylene from the azetidinium ion; A (adip) is the integral area of methylene from the adipic acid moiety (total polymer segment). The method may be adapted to any of the resins disclosed herein. Thus, for the adipic acid-based polymer, the azetidinium ion peak at 74 ppm and the skeletal methylene peak at 25 ppm were all integrated and the methylene peak at 25 ppm was normalized to 1. [ For the glutaric acid-based polymer, the azetidinium ion peak at 74 ppm and the skeletal methylene peak at 22 ppm were all integrated and the methylene peak at 22 ppm was normalized to 1.

Wet strength  The charge density of the resin

The charge density of the cationic polyamidoamine-epichlorohydrin (PAE) wet strength resin having a typical non-volatile content of about 10% to about 50% was determined using a Muetek PCD-03 particle charge detector and a titrator . The charge density was determined by measuring the streaming current potential of a dilute solution of multiple cationic resins by titration with a polyanionic solution of polyvinylsulfate (PVSK). The non-volatile content of the PAE resin was predetermined and the charge density was reported in milliequivalents (+) / gram of solids (meq + / g).

Under the action of Van der Waals forces, the multimodal resin is preferentially adsorbed on the surface of the test cell and its vibrating displacement piston, and as the diffusion cloud of the counterion is sheared directly into the cationic colloid by the liquid flow in the test cell, The so-called streaming current is induced. The electrodes in the test cell wall measure the streaming current. The PAE resin is titrated with PVSK until the PAE resin reaches the point of zero charge, and the initial resin charge is calculated from the titrant consumption. The streaming current is used to calculate the milliequivalents of cationic charge / gram solids resin (meq + / gram) as follows:

Charge density = (PVSK (mL) * PVSK (N)) / (gram active resin) = meq + / gram

Manufacture of sheet

The pulp stock used in the hand sheet work was unique for each study, as indicated in Tables 2, 3 and 4. The resin was added to the lb / tonne of pulp solids indicated in the table (thick stock%) and allowed a 2-minute mixing time for the diluted stock consistency indicated in each table. The treated stock was immediately poured into the headbox of a Noble & Wood hand sheet machine containing pH pre-conditioned water (pH 7.0). The target sheet basis weight was 30 lb / 3000 ft ² . Each wet sheet was provided with two passes through a full load wet press and then placed in a 105 DEG C drum dryer without blotting for one minute. The entire set of handsheets was further cured at 105 [deg.] C in a forced draft oven for 10 minutes. The hand sheet samples continued at constant humidity (50%) and at a constant temperature (73 ℉) for 24 hours prior to testing.

Tensile measurement

Dry tensile and wet tensile (test specimens immersed in distilled water at 23.0 ± 0.2 ° C) were tested to determine improved paper dry and wet tensile strength performance. Dry and wet tensile are reported for wet and dry hot end lengths (wet BL and dry BL) in kM / m. The dry tensile test method refers to the TAPPI Test Method T494 om-01 (effective September 5, 2001). The wet tensile measurement method refers to the TAPPI test method T456 om-03 (effective date May 13, 2003).

%  Wet / dry tensile ( %  W / D tensile)

The% wet / dry tensile is measured as a percentage of the wet to dry tensile, i.e.,% W / D BL (hot end length) is (wet tensile hot end length) / (dry tensile hot end length)

Wet and dry Tear

The dry tear test method refers to the TAPPI Test Method T 414-om-04 (effective date 3 May 2004). The wet tear measurement was determined by the TAPPI Test Method T 414-om-04 (effective May 3, 2004).

Example

The following examples are provided to illustrate various aspects of the present disclosure and the claims. Unless otherwise specified, the reagents were obtained from commercial sources. The following analytical method was used to characterize the resin.

Example  One. Polyamidomine Prepolymer  Manufacture of I

The glass reactor with 5-neck top was equipped with a stainless steel stirrer shaft, reflux condenser, temperature probe, and hot oil bath. 500.5 grams of DETA (diethylenetriamine) was added to the reactor. The stirrer was activated and 730 grams of adipic acid was slowly added to the reactor over 45 minutes with stirring. The reaction temperature increased from 25 ° C to 145 ° C during adipic acid addition. After adipic acid addition was complete, the reactor was immersed in a hot oil bath heated to 160 < 0 > C. At 150 < 0 > C the reaction mixture began to reflux. The reflux condenser was reconstituted for distillation and the distillate was collected in a separate vessel. The reaction mixture was sampled at 30 minute intervals. Each sample was diluted with water to 45% solids, and the viscosity was measured with a Brookfield viscometer. When the sample reached 290 cP, the distillation condenser was reconstituted for reflux. Water was slowly added to the reaction mixture through a reflux condenser to dilute the reaction and cool. Water was added to give a final solids of 45%. The viscosity was 290 cP.

Example  2. Polyamidomine Prepolymer  Manufacturing of II

The glass reactor with 5-neck top was equipped with a stainless steel stirrer shaft, reflux condenser, temperature probe, and hot oil bath. To the reactor was added 1574.5 gram DBE-5 (glutaric acid dimethyl ester, or dibasic ester). The stirrer was activated and 1038.9 grams of DETA was added to the reactor with stirring. The reactor was immersed in a hot oil bath heated to 100 < 0 > C. At 90 [deg.] C, the reaction mixture began to reflux. The reflux condenser was reconstituted for distillation and the distillate was collected in a separate vessel. The reaction mixture was sampled at 30 minute intervals. Each sample was diluted with water to 45% solids, and the viscosity was measured with a Brookfield viscometer. When the sample reached 220 cP, the distillation condenser was reconstituted for reflux. Water was slowly added to the reaction mixture through a reflux condenser to dilute the reaction and cool. Water was added to give a final solids of 45%. The viscosity was 220 cP.

Example  3. Wet strength  Manufacture of resin

Step 1 . The glass reactor with 5-neck top was equipped with glass stirrer shafts and Teflon paddles, the same pressure feed funnel, temperature and pH probes, stainless steel cooling coil, sample valve, and heating mantle. From the Example 2, 445.64 grams of polyamidoamine prepolymer II was added to the reactor. Water, 5.25 grams was added and the stirrer started. The reaction mixture was heated to 35 DEG C and 2.028 grams of N, N -methylene-bis-acrylamide (Pfaltz & Bauer, Inc.) was added. The reaction mixture was heated to 60 < 0 > C and held at that temperature for 4 hours. The viscosity of the reaction mixture evolved to 384 cP (Brookfield-SSA). The intermediate (partially crosslinked) prepolymer mixture was used in the system in the following step 2 .

Step 2 . From step 1 the reaction temperature of the intermediate prepolymer mixture was adjusted to 25 DEG C and 88.46 grams of water was added. The reaction temperature was then adjusted to 21 DEG C and 121.21 grams of epichlorohydrin was added over 75 minutes. The reaction mixture was allowed to warm to 25 [deg.] C over 45 minutes and 446.27 grams of water was added. The reaction mixture was heated to 45 캜 and heated to 55 캜 after 2 hours. After about 4 hours, a mixture of formic acid and sulfuric acid was added to adjust the pH to 2.87. (In general, the pH can be adjusted using any organic acid, inorganic acid, or a combination thereof, such as acetic acid, formic acid, hydrochloric acid, phosphoric acid, sulfuric acid, or any combination thereof. It was then cooled to 25 DEG C and water was added to adjust the solids to 25.0%. The viscosity of the obtained wet strength resin was 187 cP.

Example  4. Wet strength  Manufacture of resin

Step 1 . The glass reactor with 5-neck top was equipped with glass stirrer shafts and Teflon paddles, the same pressure feed funnel, temperature and pH probes, stainless steel cooling coil, sample valve, and heating mantle. From the Example 1, 1000.00 grams of polyamidoamine prepolymer I was added to the reactor. The stirrer was started and the prepolymer was heated to 40 < 0 > C. N, N -methylene-bis-acrylamide, 15.16 grams (Pfaltz & Bauer, Inc) was added slowly while the reaction mixture was heated to 60 占 폚. The reaction mixture was then held at 60 DEG C for about 2 hours and the viscosity evolved to 4,630 cP (Brookfield-SSA), at which point the viscosity evolution was stopped. The reaction was cooled to 25 < 0 > C. The intermediate (partially crosslinked) prepolymer was isolated and stored.

Step 2 . (Cross-linked in part) from part 1 in the reactor it is configured as described in step 1 medium in prepolymer 366.04 grams were added. The reaction temperature was adjusted to 25 DEG C and 120.13 grams of water was added. The viscosity of the reaction mixture was 837 cP. 77.89 grams of epichlorohydrin was added to the partially partially crosslinked prepolymer at 25 占 폚 over 90 minutes. 428.19 grams of water was added to the reaction mixture. The reaction was maintained at 25 < 0 > C for 18 hours during which time it was periodically sampled for < ¹³ > C NMR analysis. During this time, the viscosity of the reaction increased from 18 cP to 319 cP (Brookfield-SSA). The reaction was treated with concentrated sulfuric acid to adjust the pH to 2.94. The reaction mixture was adjusted to 25.0% solids and had a viscosity of 335 cP.

Example  5. Wet strength  Manufacture of resin

Step 1 . The glass reactor with 5-neck top was equipped with glass stirrer shafts and Teflon paddles, the same pressure feed funnel, temperature and pH probes, stainless steel cooling coil, sample valve, and heating mantle. From the Example 2, 449.10 grams of polyamidoamine prepolymer II was added to the reactor. The stirrer was started and the reaction mixture was heated to 30 DEG C and 6.92 grams of poly (propylene glycol) diglycidyl ether (Polystar) was added over 1 hour. The reaction mixture was held at 30 DEG C for 1 hour and then heated to 60 DEG C at which point the viscosity was 416 cP. The reaction mixture was heated at 60 DEG C for about 4 hours and the viscosity evolved to 542 cP (Brookfield-SSA). The intermediate cross-linked prepolymer was used in the system in Step 2 below .

Step 2 . From step 1 the reaction temperature of the intermediate prepolymer mixture was adjusted to 25 DEG C and 80.10 grams of water was added. 118.79 grams of epichlorohydrin was added to the reactor over a period of 75 minutes. The reaction was allowed to warm to 30 < 0 > C over 45 minutes and 431.35 grams of water was added. The reaction was warmed to 45 < 0 > C over 45 minutes and then heated to 50 < 0 > C for 2 hours. After about 3.5 hours, the viscosity of the reaction was about 320 cP (Gardner-Holdt foam tube), then a mixture of formic acid and sulfuric acid was added to adjust the pH to 3.00. The reaction mixture was cooled to 25 ° C and water was added to adjust the solids to 25.0%. The viscosity of the obtained wet strength resin was 219 cP.

Example  6. Hand sheet  Produce

Comparison of wet performance resin performance with standard commercially available wet strength resins is provided in the Examples and Data Tables. Each data table represents the stock used in the comparison and the stock quotient (CSF) is reported. The resin was added at the rate shown in the thick stock (pulp solids of lb resin / ton) allowing a two-minute mixing time. The treated stock was immediately poured into the headbox of a Noble & Wood hand sheet machine containing pH pre-conditioned water.

The target sheet reference weight is expressed in lb / ft < ² > in each set of data. Each wet sheet was provided with two passes through a full load wet press and then placed in a 105 DEG C drum dryer without blotting for one minute. The entire set of handsheets was further cured at 105 [deg.] C in a forced draft oven for 10 minutes. The hand sheet samples continued at a constant humidity (50%) and at a constant temperature (73 F.) for 24 hours prior to testing. Any additional conditions are reported in the table. The hand sheet samples continued at a constant humidity (50%) and at a constant temperature (73 F.) for 24 hours prior to testing.

The composition resin was added at a rate of pulp solids (lb / tonne) as indicated by the respective data tables in a thick stock (reference table) allowing a two-minute mixing time. The treated stock was immediately poured into the headbox of a Noble & Wood hand sheet machine containing pH pre-conditioned water (pH 7.0). The target sheet reference weight is indicated in each table. Each wet sheet was provided with two passes through a full load wet press and then placed in a 105 DEG C drum dryer without blotting for one minute. The entire set of handsheets was further cured at 105 [deg.] C in a forced draft oven for 3 minutes. The hand sheet samples continued at a constant humidity (50%) and at a constant temperature (73 F.) for 24 hours prior to testing.

Example  7. Evaluation of composition characteristics and performance

A comparison of the wet strength resin properties with the standard commercially available wet strength resin is provided in the following table. The wet strength resin properties of the resins made according to this disclosure were compared and checked with standard commercially available wet strength resin products, including the Amres® series (Georgia-Pacific) and Kymene® (Ashland) resins of the resin . Both the properties of the resin itself and the performance of the resin for imparting wet strength are compared in the following table.

Table 1 illustrates that the wet strength resins produced according to this disclosure show a significant improvement in properties when compared to commercially available resins. For example, at comparable solids content, the resin of Example 3 has significantly higher charge density, fraction of azetidinium ion to amide residues, molecular weight, azetidinium equivalent, and other properties when compared to conventional resins . Furthermore, the 1,3-dichloro 2-propanol (1,3-DCP) content which is not desired in the obtained resin is substantially reduced.

Table 2 illustrates the improvement in wet end length of a premium grade heavyweight towel when treated with a resin according to the present disclosure. A comparison of the measured properties at different application rates with the same properties obtained using conventional resins is provided. Substantial improvements in properties are observed using the resins produced as described herein.

Table 3 similarly illustrates an improvement in the wet end length of the recycled weft towel when treated with resin according to the present disclosure at different application rates (pulp solids of 5, 10, and 15 lb composition resin / ton). A comparison of the same properties obtained using conventional resins is provided. In all cases, a substantial improvement in performance is exemplified using the disclosed wet strength resin.

Similarly, Table 4 shows the wet tensile of the hot end length of unbleached SW cork at different application rates (pulp solids of 4, 6, and 8 lb composition resin / ton) and the% wet / The improvement in dry tension is illustrated. In each case, an improvement in performance was observed using the disclosed wet strength resin. Wet tear has also been reported and measured using specified resins and again an improvement in performance using the wet strength resin disclosed at all application rates is exemplified.

Implementations of the present disclosure relate to any one or more of the following paragraphs:

1. A process for preparing a resin comprising the steps of: a) reacting a polyamine with a symmetrical cross-linker to produce a partially cross-linked polyamine; b) adding epihalohydrin to the partially crosslinked polyamine to produce a halohydrin-functionalized polymer; And c) cyclizing the halohydrin-functionalized polymer to form a resin having an azetidinium moiety.

2. A method according to paragraph 1, wherein the polyamine has the structure:

Wherein R is alkyl, hydroxyalkyl, amine, amide, aryl, heteroaryl or cycloalkyl and w is from 1 to about 10,000.

3. The method of paragraph 1, wherein the polyamine has a molecular weight of from about 2,000 to about 1,000,000.

4. The method of paragraph 3, wherein the polyamine has a molecular weight of from about 10,000 to about 200,000.

5. The method according to paragraph 1, wherein the symmetrical cross-linking agent is selected from diacrylate, bis (acrylamide), diepoxide and polyazidinium compounds.

6. The method according to paragraph 1, wherein the symmetrical cross-linking agent is selected from:

Insert formula

식 중 R⁴는 (CH₂)_t이고, 및 t는 1, 2, 또는 3임;

Wherein R ⁴ is (CH ₂ ) _t , and t is 1, 2, or 3;

식 중 x는 1 내지 약 100임;

Wherein x is from 1 to about 100;

식 중 y는 1 내지 약 100임;

Y is from 1 to about 100;

식 중 x' + y'는 1 내지 약 100임;

X ' + y ' is from 1 to about 100;

식 중 z는 1 내지 약 100임;

Wherein z is from 1 to about 100;

식 중 q/p 비는 약 10 내지 약 1000임;

Wherein the q / p ratio is from about 10 to about 1000;

로부터 선택된 아제티디늄-작용화된 모노머와의 코폴리머, 및 이들의 조합, 여기에서 코폴리머에서 아제티디늄-작용화된 모노머 대 아크릴레이트 모노머, 메타크릴레이트 모노머, 알켄 모노머, 또는 디엔 모노머의 분획이 약 0.1% 내지 약 12%임; 및 이들의 임의의 조합.Acrylate monomers, methacrylate monomers, alkene monomers, or diene monomers,

Functionalized monomer selected from the group consisting of an azetidinium-functionalized monomer to an acrylate monomer, a methacrylate monomer, an alkene monomer, or a diene monomer in the copolymer. The fraction is from about 0.1% to about 12%; And any combination thereof.

7. The composition of paragraph 1 wherein the symmetrical cross-linking agent is selected from the group consisting of N, N'-methylene-bis-acrylamide, N, N'- methylene- bis- methacrylamide, poly (ethylene glycol) diglycidyl ether, poly ) Diglycidyl ether, polyethylene glycol diacrylate, polyazidinium compound, and any combination thereof.

8. The method according to paragraph 1, wherein the epihalohydrin is selected from epichlorohydrin, epibromohydrin, and epi-iodohydrin.

9. The method according to paragraph 8, wherein the epihalohydrin is epichlorohydrin.

10. The method of paragraph 1 further comprising the reaction of a polyamine with a monofunctional modifier during, after, or after treatment with a symmetric cross-linker.

11. The method of paragraph 10, wherein the monofunctional modifier is selected from a neutral or cationic acrylate compound, a neutral or cationic acrylamide compound, an acrylonitrile compound, a mono-epoxide compound, or combinations thereof.

12. The composition of paragraph 10 wherein the single functional modifier is an alkyl acrylate, an acrylamide, an alkyl acrylamide, a dialkyl acrylamide, an acrylonitrile, a 2-alkyloxylan, 2- (allyloxyalkyl) oxirane, Alkyl acrylate, ω- (acryloyloxy) -alkyltrimethylammonium compound, ω- (acrylamido) -alkyltrimethylammonium compound, and any combination thereof.

13. The composition of paragraph 10 wherein the single functional modifier comprises at least one of the following: methacrylate, alkyl acrylate, acrylamide, N-methylacrylamide, N, N-dimethyl acrylamide, acrylonitrile Hydroxyethyl acrylate, 2- (2-hydroxyethoxy) ethyl acrylate, 2-ethylhexyl acrylate, 2- N, N-trimethylpropane-1-aminium, 2- acryloyloxy-N, N, N-trimethylethanaminium, 3- (acryloyloxy) N, N, N-trimethylpropan-1-aminium, and 1-isopropyl-3- (methacryloyloxy) -1-methyl Azetidinium chloride.

14. The method of paragraph 1, wherein the ratio of azetidinium ion to secondary amine moiety in the resin is from about 0.4 to about 1.0.

15. The method of paragraph 1, wherein the concentration of 1,3-dichloro-2-propanol (1,3-DCP) is less than about 15,000 ppm.

16. The method according to paragraph 1, wherein the pH of the resin is adjusted using an acid.

17. The method of paragraph 16, wherein the acid is acetic acid, formic acid, hydrochloric acid, phosphoric acid, sulfuric acid, organic acid or inorganic acid or a combination thereof.

18. The method of paragraph 16 wherein the pH of the resin is adjusted from about pH 2.0 to about pH 4.5.

19. The method of paragraph 1, wherein the solids content of the resin is adjusted from about 10% to about 50%.

20. The method of paragraph 1, wherein the resin has a charge density of from about 1.0 to about 4.0 mEq / g of solids.

21. The method of paragraph 1, wherein the resin has a ratio of azetidinium ions to amide residues of from about 0.5 to about 0.9.

22. The method of paragraph 1, wherein the resin has a molecular weight of from about 0.02 x 10 ⁶ to about 3.0 x 10 ⁶ .

23. The method of paragraph 1, wherein the resin has an azetidinium equivalent of from about 1,800 to about 3,500.

24. The method of paragraph 1, wherein the resin has a 1,3-dichloro-2-propanol (1,3-DCP) content of less than about 10,000 ppm.

25. A resin comprising a resin, wherein the resin is prepared by a process comprising the steps of: a) reacting the polyamine with a symmetrical cross-linker to produce a partially cross-linked polyamine; b) adding epihalohydrin to the partially crosslinked polyamine to produce a halohydrin-functionalized polymer; And c) cyclizing the halohydrin-functionalized polymer to form a resin having an azetidinium moiety.

26. The composition of paragraph 25, wherein the polyamine has the structure:

Wherein R is alkyl, hydroxyalkyl, amine, amide, aryl, heteroaryl or cycloalkyl and w is from 1 to about 10,000.

27. The composition of paragraph 25, wherein the polyamine has a molecular weight of from about 2,000 to about 1,000,000.

28. The composition of paragraph 27, wherein the polyamine has a molecular weight of from about 10,000 to about 200,000.

29. The composition of paragraph 25, wherein the symmetrical cross-linking agent is selected from diacrylate, bis (acrylamide), diepoxide and polyazidinium compounds.

30. The composition of paragraph 25 wherein the symmetrical cross-linker is selected from:

Insert formula

식 중 R⁴는 (CH₂)_t이고, 및 t는 1, 2, 또는 3임;

Wherein R ⁴ is (CH ₂ ) _t , and t is 1, 2, or 3;

식 중 x는 1 내지 약 100임;

Wherein x is from 1 to about 100;

식 중 y는 1 내지 약 100임;

Y is from 1 to about 100;

식 중 x' + y'는 1 내지 약 100임;

X ' + y ' is from 1 to about 100;

식 중 z는 1 내지 약 100임;

Wherein z is from 1 to about 100;

식 중 q/p 비는 약 10 내지 약 1000임;

Wherein the q / p ratio is from about 10 to about 1000;

로부터 선택된 아제티디늄-작용화된 모노머와의 코폴리머, 및 이들의 조합, 여기에서 코폴리머에서 아제티디늄-작용화된 모노머 대 아크릴레이트 모노머, 메타크릴레이트 모노머, 알켄 모노머, 또는 디엔 모노머의 분획이 약 0.1% 내지 약 12%임; 및 이들의 임의의 조합.Acrylate monomers, methacrylate monomers, alkene monomers, or diene monomers,

Functionalized monomer selected from the group consisting of an azetidinium-functionalized monomer to an acrylate monomer, a methacrylate monomer, an alkene monomer, or a diene monomer in the copolymer. The fraction is from about 0.1% to about 12%; And any combination thereof.

31. The composition of paragraph 25 wherein the symmetrical cross-linking agent is selected from the group consisting of N, N'-methylene-bis-acrylamide, N, N'- methylene- bis- methacrylamide, poly (ethylene glycol) diglycidyl ether, poly ) Diglycidyl ether, polyethylene glycol diacrylate, polyazidinium compound, and any combination thereof.

32. The composition of Paragraph 25 wherein the epihalohydrin is selected from epichlorohydrin, epibromohydrin, and epi-iodohydrin.

33. The composition of paragraph 32 wherein the epihalohydrin is epichlorohydrin.

34. The method of paragraph 25, wherein the method further comprises the step of: reacting the polyamine with a monofunctional modifier prior to, during, or after treatment with a symmetrical cross-linker.

35. The composition of paragraph 34 wherein the single functional modifier is selected from a neutral or cationic acrylate compound, a neutral or cationic acrylamide compound, an acrylonitrile compound, a mono-epoxide compound, or combinations thereof.

36. The composition of paragraph 34 wherein the single functional modifier is selected from the group consisting of alkyl acrylates, acrylamides, alkyl acrylamides, dialkyl acrylamides, acrylonitrile, 2-alkyloxirane, 2- (allyloxyalkyl) Alkyl acrylate, ω- (acryloyloxy) -alkyltrimethylammonium compound, ω- (acrylamido) -alkyltrimethylammonium compound, and any combination thereof.

37. A composition according to paragraph 34, wherein the single functional modifier comprises at least one of the following: acrylate, methacrylate, , 2-methyloxirane; Hydroxyethyl acrylate, 2- (2-hydroxyethoxy) ethyl acrylate, 2- (acryloyloxy) ethyl acrylate, 2- Si) -N, N, N-trimethylethanaminium, 3- (acryloyloxy) -N, N, N-trimethylpropane-1-aminium; N, N, N-trimethylpropane-1-aminium, and 1-isopropyl-3- (methacryloyloxy Yl) -1-methyl azetidinium chloride.

38. The composition of paragraph 25, wherein the ratio of azetidinium ion to secondary amine moiety in the resin is from about 0.4 to about 1.0.

39. The composition of paragraph 25 wherein the concentration of 1,3-dichloro-2-propanol (1,3-DCP) is less than about 15,000 ppm.

40. The composition of Paragraph 25 wherein the pH of the resin is adjusted using an acid.

41. The composition of paragraph 40 wherein the acid is acetic acid, formic acid, hydrochloric acid, phosphoric acid, sulfuric acid, organic or inorganic acids or combinations thereof.

42. The composition of paragraph 40 wherein the pH of the resin is adjusted from about pH 2.0 to about pH 4.5.

43. The composition of paragraph 25, wherein the solids content of the resin is adjusted from about 10% to about 50%.

44. The composition of paragraph 25, wherein the resin has a charge density of from about 1.0 to about 4.0 mEq / g of solids.

45. A composition having at least three of the following characteristics: a) a charge density of from about 1.0 to about 4.0 mEq / g of solids; b) the ratio of azetidinium ion to amide residues in the resin is from about 0.5 to about 0.9; c) molecular weight of about 0.1 × 10 ⁶ to about 3.0 × 10 ^6; d) an azetidinium equivalent of about 1,800 to about 3,500; And e) 1,3-dichloro-2-propanol (1,3-DCP) content of less than about 10,000 ppm when the solids content is about 25%.

46. A paper reinforced with the composition of any one of paragraphs 25-45.

47. A method of treating paper for imparting wet strength, comprising the step of treating the pulp fibers used to make the paper with the resin composition prepared by the following steps: a) reacting the polyamine with a symmetrical cross-linking agent to form a partially crosslinked polyamine ; b) adding epihalohydrin to the partially crosslinked polyamine to produce a halohydrin-functionalized polymer; And c) cyclizing the halohydrin-functionalized polymer to form a resin having an azetidinium moiety.

48. A strength resin comprising a partially crosslinked polyamine with a bridging moiety and having an azetidinium ion, wherein the bridging moiety is selected from the group consisting of diisocyanate, 1,3-dialkyldiazetidine-2,4-dione, A strength resin derived from a functionally symmetrical cross-linker comprising water, diacyl halide, dienone, dialkyl halide, or any mixture thereof.

49. A method of reinforcing paper comprising contacting a fiber with a strength resin comprising a partially cross-linked polyamine with a bridging moiety and having an azetidinium ion, wherein the bridging moiety comprises a diisocyanate, a 1,3- Dialkyldiazetidine-2,4-dione, dianhydride, diacyl halide, dienone, dialkyl halide, or any mixture thereof.

50. A method of making a strength resin comprising the steps of: reacting a polyamine and a functionally symmetric cross-linker to produce a partially cross-linked polyamine, wherein the functionally symmetric cross-linker is a diisocyanate, Diazetidine-2,4-dione, dianhydride, diacyl halide, dienone, dialkyl halide, or any mixture thereof; And reacting the partially crosslinked polyamine with an epihalohydrin to produce a strength resin having an azetidinium ion.

51. The strength resin or method according to any one of paragraphs 48 to 50, wherein the functionally symmetric cross-linking agent comprises a diisocyante.

52. A strength resin or process according to any one of paragraphs 48-51, wherein the diisocyanate is a blocked diisocyanate.

53. A strength resin or process according to any one of paragraphs 48 to 52, wherein the functionally symmetric cross-linker comprises 1,3-dialkyldiazetidine-2,4-dione.

54. The strength resin or method according to any one of paragraphs 48 to 53, wherein the functionally symmetric cross-linking agent comprises dianhydride.

55. A strength resin or process according to any one of paragraphs 48 to 54, wherein the functionally symmetric cross-linker comprises a diacyl halide.

56. The strength resin or method according to any one of paragraphs 48 to 55, wherein the functionally symmetric cross-linking agent comprises dienone.

57. A strength resin or process according to any one of paragraphs 48 to 56, wherein the functionally symmetric cross-linker comprises a dialkyl halide.

58. The process of any one of paragraphs 48 to 57 wherein the functionally symmetrical cross-linking agent is selected from the group consisting of diacrylate compounds, bis (acrylamide) compounds, diepoxide compounds, polyazetidinium compounds, N, N'- Amide, poly (alkylene glycol) diglycidyl ether, or any mixture thereof.

59. A strength resin or process according to any one of paragraphs 48 to 58, wherein the polyamine comprises polyamidoamine.

60. The strength resin or method according to any one of paragraphs 48 to 59, wherein the azetidinium ion is formed by the reaction of an epihalohydrin and a partially cross-linked polyamine with a bridging moiety.

61. A strength resin or process according to any one of paragraphs 48 to 60, wherein the strength resin has a charge density of from 2.25 mEq / g of solids to 3.5 mEq / g of solids.

62. A strength resin or process according to any one of paragraphs 48 to 61, wherein the strength resin has an azetidinium equivalent of from 2,000 to 3,500.

63. The strength resin or method according to any one of paragraphs 48 to 62, wherein the strength resin has a weight average molecular weight of 900,000 to 1,700,000.

64. A strength resin or process according to any one of paragraphs 48 to 63, wherein the strength resin contains less than 10,000 ppm of 1,3-dichloro-2-propanol.

65. The method of any one of paragraphs 48 to 60 wherein the strength resin has a charge density of from 2.25 mEq / g of solids to 3.5 mEq / g of solids, an azetidinium equivalent of from 2,000 to 3,500, a weight average molecular weight of from 900,000 to 1,700,000 , Less than 10,000 ppm of 1,3-dichloro-2-propanol.

66. The composition of any one of paragraphs 48 to 65, wherein the functionally symmetric cross-linking agent is selected from the group consisting of di-acrylate compounds, bis (acrylamide) compounds, di-epoxide compounds, polyazetidinium compounds, N, N'- Methacrylamide, and poly (alkylene glycol) diglycidyl ether, or any mixture thereof.

Certain embodiments and features are described using a set of numerical upper limits and a set of lower numerical limits. It is recognized that a range including any combination of two values, for example, a combination of any upper limit value and any lower limit value, a combination of any two lower limit values, and / or any two upper limit values, . Certain lower limits, upper limits, and ranges are recited in one or more claims below. The overall value is a value of "about" or "approximately" and takes into account experimental errors and variations to be expected by those skilled in the art.

Various terms are defined above. To the extent that the terms used in the claims are not limited to the above, the widest definition providing the term as reflected in at least one printed publication or published patent of the person skilled in the art should be provided. And if applicable, the entire patent, test procedure, and other documents referred to herein are fully incorporated by reference to the extent that the disclosure is consistent with the present disclosure and for the entire jurisdiction where such incorporation is permitted.

While the foregoing is directed to certain illustrative embodiments, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims (20)

A strength resin comprising a partially crosslinked polyamine with a bridging moiety and having an azetidinium ion, wherein the bridging moiety is selected from the group consisting of diisocyanate, 1,3-dialkyldiazetidine-2,4-dione, dianhydride A diacyl halide, a dienone, a dialkyl halide, or any mixture thereof. The method of claim 1 wherein said functionally symmetrical cross-linking agent is further selected from the group consisting of di-acrylate compounds, bis (acrylamide) compounds, di-epoxide compounds, polyazetidinium compounds, N, And poly (alkylene glycol) diglycidyl ether, or any mixture thereof. The strength resin of claim 1, wherein the functionally symmetric cross-linking agent comprises the diisocyante. 4. The strength resin of claim 3, wherein the diisocyanate is a blocked diisocyanate. The strength resin of claim 1, wherein the functionally symmetric cross-linker comprises the 1,3-dialkyldiazetidine-2,4-dione. The strength resin of claim 1, wherein the functionally symmetric cross-linking agent comprises the dianhydride. The strength resin of claim 1, wherein the functionally symmetric cross-linking agent comprises the diacyl halide. The strength resin of claim 1, wherein the functionally symmetric cross-linking agent comprises the dienone. The strength resin of claim 1, wherein the functionally symmetric cross-linking agent comprises the dialkyl halide. The strength resin of claim 1, wherein the polyamine comprises polyamidoamine. The strength resin according to claim 1, wherein the azetidinium ion is formed by the reaction of the polyamine and the epihalohydrin partially crosslinked with the bridging moiety. The strength resin of claim 1, wherein the strength resin has a charge density of from 2.25 mEq / g of solids to 3.5 mEq / g of solids. The strength resin of claim 1, wherein the strength resin has an azetidinium equivalent of from 2,000 to 3,500. The strength resin according to claim 1, wherein the strength resin has a weight average molecular weight of 900,000 to 1,700,000. The strength resin of claim 1, wherein the strength resin contains less than 10,000 ppm of 1,3-dichloro-2-propanol. The process of claim 1, wherein the strength resin has a charge density of from 2.25 mEq / g of solids to 3.5 mEq / g of solids, an azetidinium equivalent of from 2,000 to 3,500, a weight average molecular weight of from 900,000 to 1,700,000, , 3-dichloro-2-propanol. A method of making a strength resin, comprising the steps of:
Reacting a polyamine and a functionally symmetrical cross-linking agent to produce a partially cross-linked polyamine wherein said functionally symmetric cross-linker is a diisocyanate, 1,3-dialkyldiazetidine-2,4- A diacyl halide, a dienone, a dialkyl halide, or any mixture thereof; And
Reacting said partially crosslinked polyamine with an epihalohydrin to produce a strength resin having an azetidinium ion. 19. The method of claim 17, wherein the strength resin has a charge density of from 2.25 mEq / g of solids to 3.5 mEq / g of solids, an azetidinium equivalent of from 2,000 to 3,500, a weight average molecular weight of from 900,000 to 1,700,000, , 3-dichloro-2-propanol. 19. The method of claim 18, wherein the functionally symmetric cross-linking agent is further selected from the group consisting of diacrylate compounds, bis (acrylamide) compounds, diepoxide compounds, polyazetidinium compounds, N, N'- methylene- Alkylene glycol) diglycidyl ether, or any mixture thereof. A method of reinforcing a paper comprising contacting a fiber with a strength resin comprising a partially cross-linked polyamine with a bridging moiety and having an azetidinium ion, wherein the bridging moiety comprises a diisocyanate, a 1,3- Dialkyldiazetidine-2,4-dione, dianhydride, diacyl halide, dienone, dialkyl halide, or any mixture thereof.