MXPA97004522A - Adhesives sensitive to the pres - Google Patents

Abstract

A pressure sensitive adhesive composition (PSA) includes a latex system of an aqueous polymer dispersion derived from ethylenically unsaturated monomers in the presence of a water soluble protective colloid. PSA compositions are used in the manufacture of a variety of articles that are intended to be easily fixed to another substrate by the mere application of pressure.

Description

PRESSURE SENSITIVE ADHESIVES The present invention relates to a composition of pressure sensitive adhesives (PSA) and their application. More specifically, this invention relates to a PSA composition that includes aqueous dispersions of polymers derived from ethylenically unsaturated monomers in the presence of a water-soluble protective colloid and its a ia ions. Usually sticky pressure sensitive adhesives (PSAs) are used in the manufacture of various articles such as adhesive tapes and other materials whose purpose is easily fixed on another substrate by the application of pressure alone. Many adhesives preferably have a balance between one or more properties such as tackiness at the use temperature, adhesion (release resistance), cohesion (shear strength), elongation, elasticity, color clarity and color stability, as well as as resistance to lus: solar and other sources of ultraviolet and degrading radiation. Maintaining the required balance between such properties while improving one or more characteristics of such PSAs is difficult and unpredictable. Any modification of the adhesive compositions that improve an adhesive property can adversely affect one or several other desirable properties. For example, it is difficult to improve the internal strength of the adhesive (cohesion and resistance to shear) without reducing one or more other desirable properties. Polymers of olefinically unsaturated carbaxyl ester have received widespread acceptance as PSAs due to the relatively good balance of properties they provide in many applications Acrylic-based latexes have found wide acceptance in the PSA industry due to performance of adhesion of the PSA based on acrylic emulsions in such a way that they can replace systems based on solvents more expensive and more harmful for the environment. However, the correct ion combination of peel strength, tackiness and resistance to stress shear alone does not guarantee the success in the PSA market. The industry is looking for greater mechanical stability and a "TO--. Less tendency to lather foam is applied. Prior to the present invention, PSAs carried in water do not were mechanically stable and / or tended to foam when they were being prepared. In industrial processes of emulsion polymerization, surfactants are often used either alone or in combination with polymeric protective colloids. One drawback of this method is that surfactants should be used at high levels to obtain stable latexes to shear stress which is not economical and can have negative side effects. For example, the presence of surfactants in latex systems can have a negative effect on the sensitivity to water and cause the formation of foam in the final products. In addition, at conventional levels of use, surfactants do not provide sufficient mechanical stability to the final products. It is known in the prior art that the presence of protective colloids as co-stabilizers, such as, for example, hydroxyethyl cellulose (HEC) and alcohol (poly i) in vitro (PVOH), in the emulsion polymerization of ethylenically unsaturated monomers, including vinyl monomer, vinyl monomer with an acrylic monomer such as acrylic esters, methacrylic esters or mixtures thereof, provides latexes of submicron particle size with improved characteristics of rheology, stability and performance. In emulsion polymerization processes of monomers comprising acrylics or styrene either alone or in combination with other monomers, it is not always possible to use protective colloids, for example cellulosics or PVOH, as co-stabilizers. When protective colloids of the prior art are used in latex systems based on acrylic or styrene, a high degree of flocculation is observed which manifests itself in a lack of mechanical stability. This flocculation results from the high tendency of the protective colloid to be incorporated directly into the polymer chain of the reaction. East The phenomenon is often referred to as a graft. It is understood that the graft itself must be totally eliminated. A smaller amount of graft does not cause flocculation; In addition, it improves the stability of latex systems, as has been known for a long time in the case of vinyl acetate copolymer latexes. It is the combination of an excessive graft with the possibility of formation of bridges between particles that cause coagulation. The formation of bridges between paticles is not determined solely by the amount of grafted material or However, the size of the particles only, but also depends on the amount of water-soluble polymer present ? in the water phase, the molecular weight of the protective colloid, - "" 'the content in solids, etc. In any case, according to the specific latex system, 20 the lack of mechanical stability can be overcome by using high levels of surfactant alone or in combination with protective colloid. For example, in systems based on vinyl acetate, high levels of protective colloids are used in combination with surfing, whereas in acrylic-based systems, high levels of surfactant are used alone. However, latexes presented with such high levels of surfactants have the performance problems described above. Accordingly, there is a need in the industry for the 5 PSAs to overcome the drawbacks inherent in the latex systems of the prior art related to the use of high levels of surfactant or protective colloids of the prior art. ^ ». The document USSN 08 / 553,007, presented on November 3 of 1995, entitled "Cellulose Ethers in Emulsion Polymerization Dispersions" presents the techniques for producing the latexes of the present invention. The North American patents us. 3,928.2 < E-2 and 3,975,570 present PSA compositions comprising alkyl acrylate and carbs i and i-cellulose which possess an excellent * / adhesion when they adhere on an object and can ~~ * inhale more. U.S. Patent 4,908,403 presents pressure-sensitive acrylic adhesive employing colloids protectors (col 13). Another approach for the polymerization of acrylic monomer system, presented in LO, US patent no. 4,845,175, is to use from 0.02 to 2.0 * /. by weight of a hydrophobically modified hydroxyethylcellulose as colloid protector. / > Another approach for the polymerization of acrylic monomer systems, presented in CRAIG '771, US Patent No. 4,659,771, is the use, in addition to a protective colloid, of approximately 5 VA by weight of an unsaturated monomer. substantially water-soluble conjugate such as for example furoic acid, styrene sulfonic acid, and metal salts, amine salts, ammonium salts and quaternary salts of rosin and acids having from 4 to 36 carbon atoms. invention is focused on a process for the preparation of a PSA composition comprising an aqueous emulsion latex system comprising: a) a polymer of at least one ethylenically unsaturated monomer selected from the group consisting of acrylic acid, methacrylic acid, butyl acrylate, methyl methacrylate, 2-ethylhexyl acrylate, acrylic esters, styrene, inyl esters, vinyl, and vinylidene halides, ideal inner ion, ethylene, C3 alpha olefins or well older, allyl amines, allyl esters of acids Saturated monocarboxylic acids and amides thereof, propylene, l-butene, 1-pentene, 1-hexene, 1 -decene, allyl amines, allyl acetate, allyl propionate, allyl lactate, their amides, mixtures of the same, isomers of 1,3-butadiene, 1,3-peptadiene, 1,4-pentadiene, cyclopentadiene, Hexadiene; and b) an effective amount to stabilize the latex system, of a water soluble protective colloid with a molecular weight less than about 75,000, selected from the group consisting of carboxymethylcellulose and derivatives thereof, with a carboxyl number 5 of lower limit of substitution of about 0.7, Icelulose, hydrochloric acid, methyl alcohol, methylhydroxypropyl cellulose, hydroxypropyl cellulose, acid. (pal i) acrylic and alkali metal salts thereof, derivatives of ethoxylated starch, polyacrylate. Sodium and other alkali metals, water soluble starch glue, gelatin, water-soluble alginates, casein, agar, natural and synthetic gums, partially hydrolyzed partial alcohol (pol i), polyacrylamide, (pol i) ini Ipi rol idona, maleic anhydride of ether (pol i) meti 1 iní 1 ico, gelatin and casein. f ~ It has been unexpectedly found that the use of colloid ~ "Protector of low molecular weight in polymerization by monomeric emulsion and ille- nicly unsaturated produces a excellent mechanical stability of the resulting polymer and that these polymers are useful in PSA. The combination of the latexes with glueing agents used in this field results in an unexpectedly high resistance to the cutting of the adhesive. The upper limit of the molecular weight of the colloid The protector is about 75,000, preferably about 50,000, and with a greater degree of preference about 20,000. The lower limit of the molecular weight of the protective colloid is about 5,000, preferably about 10,000 and with a higher degree of Approximately 15,000 preferred. The present invention is specifically useful for acrylic latex or styrene systems. As indicated above, as regards the acrylic or styrene-based latex systems of the prior art, the use of commercially desirable levels of protective colloid is impractical because high levels of flocculation occur. The use. High levels of surfactant to overcome this problem can have a negative effect on the sensitivity to water and cause foaming of the final products.

Furthermore, in the conventional use levels, the surfactants do not have a sufficient impact on the mechanical stability of the final products. It has unexpectedly been found that the use of low molecular weight protective colloid, the latex system based on acrylic or styrene, allows the reduction of the level of surfactant or even the omission of said surfactant. It has been generally found that the final products have a lower sensitivity to water, less foam formation, greater mechanical stability in compared to the prior art systems. The mechanical stability can manifest itself on a longer shelf beam. Additionally, in PSAs, maintaining the required balance between tackiness, adhesion, cohesion and other properties associated with PSAs is easily achieved. The preferred psissaccharide protective colloid is a water-soluble cellulose ether that has been derivatized with ethylene oxide, methyl chloride, prapilene oxide, onocloroacetic acid, etc., or mixtures thereof. Especially preferred are carboxymethylcellulose (CMC) and derivatives thereof having a carboxyl substitution index (DS) of from about 0.7 to about 2.9, with a higher degree of preference from about 0.7 to about 1.5, with a higher degree of preference of about 1.0 to about 1.4. Suitable carbohydrate and cellulose derivatives include meti learbo imet i Icelulos, et il rbox imet i icelulos, h idrox et icarbox imet i Icelulase, hydrox iprop and Icarbox imet i Icelulasa, methox et ali Ibox box, cellulose, ethoxy lcarbax imet i lcelulos, and diet i lami noca rbo imet i lcelulosa. It is also possible to use hydroxyethylcellulose (HEC), the hydroxyethyl molar substitution (MS), preferably from about 1.6 to about 4.0, with a greater degree of preference from approximately 1.6 to approximately 3.7, which can be even greater than Pre-Approximately 1.8 Appropriately 2.9. Additionally, hydrophobically modified cellulose ethers 5 can be employed. Suitable hydrophobically modified cellulose ethers are cellulose ethers which are further substituted with a hydrocarbon having from 4 to 25 carbon atoms, in a weight amount of the hydrophobically modified cellulose ether of approximately 0.1 * -. to approximately 3.0%, with a greater degree of preference from 0.1% to approximately 2.0%. A preferred hydrophobically modified cellulose ether is hydrostatic hydrostylcellulose (HMHEC) modified. The hydrophobically modified hydrophobic hydrolytic useful in The practice of this invention is a hydroxyethyl cellulose which is further substituted with a hydrocarbon having from 25 carbon atoms, in a hydramphobically modified hydraphically modified hydraphically hydrolyzed hydroxypropyl cellulose of approximately 0.1% to about 3% by weight. , with greater degree from preferentially 0.1% to approximately 2.0%. The HMHEC hydrosylation MS is preferably within the range of from about 2.9 to about 4.0, with a higher degree of preference, from about 2.9 to about 3.5. Other cellulose ethers, for example, which can be employed in this invention as a protective colloid are ethylhydroxyethylcellulose (EHE), methycellulase (MC), methylhydroxypropylcellulose (MHPC), and hydroxypropylcellulose (HPC). Other polysaccharides and Imaterials which can be employed as protective colloids in the present invention are derivatives of ethoxylated starch, partially hydrolyzed and fully polyvinyl alcohol, polyacrylic acid, polyacrylates of alkali metals (potassium, sodium, etc.). , pal iac i lick, ether maleic anhydride (pol i) met i 1 iní 1 ico, (pal i) vini idrol ideal, water soluble starch glue, gelatin, water soluble alginates, casein, agar and natural and synthetic gums. The protective colloid is preferably used in an amount effective to stabilize the latex system of the invention. In this canexta, an effective amount is an amount that serves to stabilize the latex system-during aqueous emulsion polymerization and after the term of the imer i zae: ion. Particularly, the protective colloidal concentration in the emulsion polymerization process of the present invention can vary within a wide range, with the upper limit being determined only by economic and practical considerations based on what properties are desired in the product. final. It is preferred that the upper limit be * "~ of approximately 5.0%, with a higher degree of preference 3. 5%, and with optimum degree of preference approximately 2.5%, by weight, based on the total content of ethylenically unsaturated monomer in the reaction mass. The lower preferred limit is about 0.005%. A more preferred lower limit is about 0.05, with about 0.1% by weight, based on the total weight of the ethylenically unsaturated monomer content being the lower limit with a higher degree of preference. The protective colloid of the invention can be used either alone or in combination with other protective colloids or surfactants. For example, the CMC derivative can be used as a single stabilizer or in combination with one or more surfactants. An example of CMC's According to what is employed in this invention, it is available under the trade name "Ambergu", water-soluble polymers j z, of types 1221 and 3021, marketed by Aqualon Company, Wilmington, Delaware. A suitable hydrophobically modified hydrophilic hydrate is is available under the trade name "N oso1 Plus", marketed by Hercules Incorpor ed, Wilmington, D l w re. Also, in accordance with this invention, the monomers used in this invention are at least one monomer and Inethically unsaturated such as for example esters or vinyl ethers, styrenes, and others. The acrylates used in this invention are acrylic acid. lico, methacrylic acid, butyl acrylate, methyl methacrylate, and other acrylate or methacrylate esters. In general, any ethylenically unsaturated monomer which can optionally be cyclic, which can be polymerized by free radical initiation can be employed in the practice of this invention. Preferred ethylenically J-t * unsaturated monomers include those having up to 23 cbonds. Examples of suitable monomers include vinyl esters, vinyl ethers, halides of inila and inylidene, N ~ vini Ipirol idona, ethylene, C3, al-olefins, allyl amines, allyl esters of mañoca acids rbox i.1 icos 1. 5 saturated, and amides thereof as well as dienes and derivatives thereof. - "Suitable vinyl esters include aluminum vinyl steres as for example vinyl format, vinyl acetate, vinyl propionate, but vinyl vinyl, vinyl isobutyrate, vinyl valerate, vinyl caproate and vinyl versatate. Typical male kidney ethers include methyl vinyl ether, ethyl ethyl ether, and n-butyl ether 1-ico. C3 or higher alpha-olefins include propylene, 1-butene, 1-25 p-butene, iclopentene, 1-hexene, cyclheshexepo and 1-decene.

Allyl amine and N-substituted allyl amines are examples of typical allyl amines. Suitable dienes are butadiene, cyclopentadiene and dicylopentadiene. Suitable allyl esters of saturated monocarbaxy 1 acids may include allyl acetate, allyl propyanate, and allyl lactates, and their amides, among others. The polymers of the invention can be prepared from one or more of the monomers and il-ethically unsaturated. Regarding this point, it is observed that by means of the term "polymers" it is also meant homopalimers, and copolymers polymerized with two or more monomers. For acrylic and styrene-based lactees, low molecular weight CMC are preferred. For low viscosity acetate systems, low molecular weight HMHEC are preferably used, but low molecular weight HEC and low molecular weight CMC can also be used. When acrylic acid or methacrylic acid is used in the polymerization, the level of use is preferably from about 0.005% to about 2% - with a higher degree of preference of about 0.05% to about 1% - by weight , based on the total ethylenically unsaturated monomer content. The polymers of the present invention with relatively high glass transition temperatures - for example, - * about 50 ° C to about 150 ° C - can be characterized as "hard"; the inventive polymers with relatively low glass transition temperatures - for example, about -100 ° C to about ~ 3 ° C 5 - can be characterized as "soft". A factor that affects the degree of hardness and softness is the identity of the onómeras et ilénicamente unsaturados that are used. Different ethylenically unsaturated monomers contribute either to hardness or to softness in various degrees, and Consequently, they are known as "hard" and "soft" monomers. The hardness and relative softness of different monomers are known in the art. The degree of hardness or softness of a polymer is therefore affected by the hardness or the softness of the monomers that make up the polymers, and by the relative proportions between these manomers. * -j When a latex system of copolymers is made, the proportions between the "hard" and "soft" monomers are chosen in such a way that a skin is formed of latex Continues at the temperature of use. In PSA applications, latexes are frequently used with a significant amount of soft monomer. Up to 100% of the monomer content could be of "soft" origin. Styrene-acrylics can be elaborated within the range that contains approximately 0.005% by weight 70% by weight of vinyl styrene in the copolymer formed, vinyl acrylates can be made in the ratio range from approximately 1: 1 to approximately 10: 1, preferably about 7: 3 to about 9: 1, by weight of the years of vini acetate / acrylate. Anionic, cationic, na ionic, and amphoteric surfactants and mixtures thereof known in the art can be employed in the practice of this invention. f.- Suitable surfactants include polyolyl ethers, Sulfonated paraffin hydrocarbons, higher alkyl sulfates with, for example, lauryl sulfate, alkali metal salts and fatty acids with, for example, sodium stearate and sodium oleate, acid esters, sulfuric acid alcohols, C4 alkyl phenols - 50 ethoxylates and their sulphonation products, such as, for example, nanophenol ethoxylate with 4-50 - more preferably, 10.20 - ethylene oxide units, ethoxylated C4-50 alkanols and their sulphonation products, as well as acid esters sulfosuccinic acid or, for example, dioctyl and phosphorus sodium; These surfactants or emulsifiers are optional and are not always required, but when used, they are present in amounts of 0.1 to 5.0%, preferably 0.1 to 2.0% by weight, based on the total amount of the monomers. I nically unsaturated present in the process.

Any known method of emulsion polymerization can be employed, including batch, semi-batch, or continuous and thermal or reduction-oxidation techniques. The addition of semi-batch monomer with either batch or continuous batch addition of the initiator or catalyst is a preferred technique. The polymerization can also be carried out with high shear force, which means that, for example, a loop reactor can be used to carry out the reaction. Preferably, an amount of *. < - Approximately 0% to about 40% - with a greater degree of preference of about 1% to about 25%, and with an optimum degree of preference of about 5% to about 15% - by weight of the ethylenically unsaturated manomer or of the monomers and ilénico unsaturated in the initial charge to the reactor. Also, preferably, an amount of about 0% to about 60% is added - with a greater degree of preference of about 50% to about 60% - by weight of the initiator in the initial charge to the reactor. The addition Any continuous reaction ingredient or reaction ingredients is generally carried over a period of approximately 2 hours to about 5 hours. A batch initiator, either delayed or a catalyst, can be used, even when these variants are not necessary for the success of the r *** ^ invention. In general, the monomers are polymerized by aqueous emulsion techniques at a temperature of approximately 20 ° C to about. 120 ° C, preferably from about 45 ° C to about 95 ° C, in the presence of a free radical polymerization initiator, particularly a water-soluble peroxide, for example, hydrogen peroxide, persulfates such as potassium persulfate, sodium and ammonium, to good, in some cases, perborates. Other methods known in the art can also be used to immerse manomeres, such as, for example, by the use of reduction-or oxidation polymerization catalyst systems such as potassium persulfate and sodium bisulfite. The initiator It is used in a concentration of 0.2 to 2.0% by weight based on the weight of the monomer or of the monomers, preferably in an amount of 0.3 to 1.0%. The product resulting from the invention is a latex system that includes particles of the polymer prepared from this dispersed form with discontinuous phase in an aqueous continuous phase, and also includes the protective colloid. The size of the latex particles and the particle size disttion can significantly influence the physical properties of latex which affects the application of the latex on a support material. The indicated particles J - ** - preferably have an average size in the range of about 0.05 to 2 microns depending on the type of PSA, support material, and desired properties. In the same way, the viscosity of the latex can limit the use of the latex in the manufacture of adhesive articles due to the influence of the viscosity on the adhesive disttion, solid content (of latex) and wetting of the support of the adhesive article. . The proper character of the PSA compositions is influenced primarily by the stickiness of the composition. Therefore, the main component is the sticky adhesive latex system. The stickiness and shear strength of the PSA can be modified by controlling the latex system. For example, by controlling the molecular weight of the polymer as well as the ingredients in the latex, this will allow the J - ^ modification of the PSA to control the desired characteristics. Other factors that influence the appropriateness of the PSAs are the ease of manufacture of both the adhesive as of the articles containing the adhesive, and the dangers to the staff and to the environment. The dispersion of the present invention must therefore adequately wet the support of a joint to ensure a distribution of adhesive, coverage and bonding adequate with the support.

The latex system of the present invention has excellent shear stability. Consistent with the previous discussion, it can be used in latex PSA compositions. These PSA compositions preferably include at least one glue agent, wetting agent, foam remover and a preservative; Additional conventional components for latex PSA formulations, including thickeners, can be used. The use of solvents (other than water) becomes increasingly undesirable due to the cost of solvents as well as the cost and hazards included in the control of solvent vapors. However, in some cases, small amounts of solvent should be employed in the aqueous system of the present invention to control certain properties. All the parts and percentages of polymer and glue agent used. in this explanation they are considered by dry weight unless otherwise indicated. The invention is illustrated by means of the following examples which are provided for the purpose of representing the invention but which are not intended to limit the scope of the present invention. EXAMPLE 1 Water-based Pressure Sensitive Adhesive (PSA) using bu lacrylate latex stabilized with low molecular weight CMC (invention). A butylated lactic acid latex stabilized with low molecular weight CMC was used in a PSA formulation. The PSA consisted of 70% latex, 30% resin dispersion of 5 glue, and 0.6% (wet) of a Lumiten (mr) I-RA product (diacti isulfosuccinate, marketed by BASF). The resin dispersion is based on rosin ester with a softening point of 70 * C. (Product Tacolyn (mr) 3179, marketed by Hercules Incorpor ted). f ^ 10 Latex composition and latex stabilization are presented in Table 1, infra. The evaluation of the pressure sensitive adhesive is presented in Table 2, infra. This example shows good adhesion, resistance to shear stress of a PSA formulation using the latex of the invention. EXAMPLE 2 Water-based PSA employing a latex of but i lacri or stabilized with low molecular weight CMC (invention) 20 A latex of bu i larylate stabilized with a low molecular weight CMC was used in the formulation of a PSA . The PSA was composed of 70% latex, 30% glue resin dispersion, and 0.6% by weight (wet) of Lumiten (mr) I-RA product. The resin dispersion is based on the ester of ros ina (Tacolyn product (mr) 3179, marketed by Hercules). The latex composition and latex stabilization is presented in Table 1. The latex used in this example was the same latex used in Example 1. The PSA formulation was also exactly the same. The results showed good reproducibility of the PSA results when a different number of latex was used. The PSA evaluation appears in Table 2, infra. EXAMPLE TO PSA based on water using stabilized butylate latex with surfactants (comparison) The same adhesive formulation as used in examples 1 and 2 was used. The latex used in this example was a latex stabilized purely with surfactants with exactly the same monomer composition as the latexes of examples 1 and 2. The results appear in Tables 1 and 2. This example demonstrated superior shear adherence for latexes stabilized with low molecular weight CMC, compared to latexes stabilized purely with surfers. EXAMPLE 3 Water-based PSA using buty lacrylate latex or stabilized with low molecular weight / average molecular weight CMC (invention) - *. &A latex of buty lacrylate stabilized with low molecular weight CMC was used in a PSA formulation. The monomer composition differs from the composition of Examples 1, 2 and 3 in terms of the amount of soft monomer 5 used. The latex in this example contained 95% by weight of butylate and had, therefore, a lower glass transition temperature than that of the latex used in examples 1, 2 and 3. The PSA was composed of 70% of latex, 30% dispersion of glue resin, and 0.6% by weight (wet) of Lumiten (r) I-RA. The dispersion of the resin was based on the rosin ester, product Taeolyn (mr) 3179. The results in PSA showed that the dispersions stabilized by Ambergum (mr) had a higher cohesion resistance compared to latexes commercially or stabilized with surfactants as demonstrated in the case examples B, C and D. EXAMPLE 4 Water-based PSA using butylated lactiferous latex stabilized with low molecular weight CMC (Mw) (invention) A butylated lactic acid latex stabilized with low molecular weight CMC was used in a PSA formulation. The concentration of the material Ambergum (mr) 3021 in the latex was 2% of the active material in weight of the total monomer. The composition of the monomer of this latex was equal to that of example 3. The PSA was composed of 70% latex, 30% of? * glue resin dispersion, and 0.6% by weight (wet) of Lumiten I-RA product (mr). The resin dispersion was based on a Tacolyn (r) 3179 rosin ester. The results in PSA showed that the dispersions 5 stabilized with Ambergum (r) have a superior resistance to cohesion in comp.arae ion with commercial latexes or stabilized by surfactants from comparison examples B, C, and D. __ EXAMPLE B 10 Water-based PSA using commercial commercial latex (DL 322, commercialized by DOW Chemical Campany) (Ca p rac i on) . A commercial butylate lactide latex (DL 322) was used in a PSA formulation composed of 70% latex, 30% glue resin dispersion, and 0.6% by weight (wet) of Lumiten I-RA product (mr). The resin dispersion was based on a rosin ester of Tacolyn (mr) 3179. EXAMPLE C PSA based on water using a latex of but i lacri lato commercial (product Primal EP 5560F, marketed by Rohm% &Haas) (Comparison). Commercial latex (Primal EP 5560F) latex was used in a PSA formulation composed of 70% latex, 30% glue resin dispersion, and 0.6% by weight (wet) of product I-RA of Lumiten (mr). The resin dispersion was based on a rosin ester of Tacolyn (mr) 3179. EXAMPLE D PSA based on water using a commercial butylate lactide latex (Acronal DS 3434X, marketed by BASF) (Comparison). A commercial bu i larylate latex (Acronal DS 3434X) was used in a PSA formulation composed of 70% latex, 30% glue resin dispersion, and 0.6% by weight (wet) of I-RA product. Lumiten (mr). The resin dispersion was based on a rosin ester of Tacolyn (mr) 3179. EXAMPLE 5 Water-based PSA using a butylated lactide latex stabilized with low molecular weight CMC (Invention). The same adhesive formulation was used as in Example 3 with the exception of the glue agent employed. In this example, the Tacolyn (mr) 64 material was used as a glue resin. The material Tacolyn (mr) 64 is a dispersion of hydrogenated rosin ester with a softening point of 60 ° C. The latex used in the example was exactly the same as that used in example 3. This example showed a good compatabi 1 Latexes stabilized with Ambergum (r) 3021 with various glue agents. Again, a high cohesion strength was obtained for the PSA. EXAMPLE 6 L * ". PSA based on water using a butylated lactide latex stabilized with a low molecular weight CMC (Invention) The same adhesive formulation used as in Example 3 was used with the exception of the glue agent In this example, the material used as glue resin was Tacolyn (r) 1070. Tacolyn (mr) 1070 is a modified five-carbon (C5) aromatic resin dispersion.The latex used in the example was the same as the employee in Example 3. 1.0 This example showed a good co pability of the stabilized latexes can Ambergum (mr) 3021 with several glue agents Once again, an extremely cohesive force was obtained at a for the PSA. 7 15 Water-based PSA using latexes of ethoxy lacrylate stabilized with CMC of molecular weight (Invention) A latex of et ihex i lacri lato e.stabi 1 was used with ultra low molecular weight CMC in a formulation of PSA composed of 7 0% latex, 30% resin dispersion glue and 0% by weight (wet) of Lumiten (mr) I-RA product. The resin dispersion was based on rosin acid Tacolyn (mr) 21.78. In Table 4, ε presents the latex composition. In Table 5, the PSA properties are provided. 25 This example showed the good compatability of the latexes, - stabilized co Ambergum (mr) 3021 with various glues agents and the best performance compared with commercial latexes (see examples E and F). EXAMPLE E 5 Water-based PSA using commercially available latex (Acronal (mr) V 205). A commercial latex of Ihexi lacri lato (Acronal (mr) V 205, marketed by BASF) was used in a formulation of s. PSA composed of 70% latex, 30% dispersion of resin 10 of glue with the resin dispersion based on rosin acid Tacolyn (mr) 2178 stabilized, and 0.6% by weight (wet) of product Lu iten (mr) I -RA. In Table 5, the properties of the PSA are presented. EXAMPLE F 15 Water-based PSA using commercially available latex (Acron (mr) V 220). A latex of the lacteal lacteal (Acronal (mr) V 220, marketed by BASF) was used in a PSA formulation composed of 70% latex, 30% resin dispersion of 20 glue with the resin dispersion based on acid of stabilized rosin Tacolyn (mr) 2178, and 0.6% by weight (wet) of product Lumiten (mr) I-RA. In Table 5, the PSA properties appear. EXAMPLE 8 25 Water-based PSA using latex and stabilized latex with low molecular weight CMC (Invention). A latex of ilhexilacrilata stabilized with ultra low molecular weight CMC was used in a PSA formulation composed of 60%, 70% and 80% latex and consequently, 5 20%, 30% and 40% of a dispersion of resin of glue. The resin dispersion was based on Tacolyn (r) 2178 rosin acid. In the adhesive formulation, 0.6% by weight (wet) of Lumiten (mr) I-RA product was used. In Table 4, • > "* v presents the latex composition: the latex used is the same as the latex used in example 7. In Table 6, the properties of PSA are presented. This example showed in combination with examples 9, 10 and 11 the good ca patabi 1 of the latexes stabilized with A bergum (r) 3021 with various glueing agents. HE obtained a high adhesion for the three levels of glue em leados.

^ -, EXAMPLE 9 Water-based PSA using latex from the Ihexi lac can stabilized with low molecular weight CMC (Invention). 20 A latex made from ultra-low molecular weight CMC was used in a PSA formulation composed of 60%, 70%, and 80% latex and consequently 20%, 30%, and 40% of glue resin dispersion. The resin dispersion was based on one. hydrocarbon rosin modified (product HERCULES MBG 185, with a softening point of 75ßC, marketed by H rcules BV). In the adhesive formulation, 0.6% by weight was also used (Lumiten product wet (mr) I-RA (marketed by BASF). In Table 4, the latex composition is provided; The latex employed is the same as the latex mentioned in example 11. In Table 6, the properties of the PSA are given. EXAMPLE 1.0 Water-based PSA using stabilized latex and stabilized latex with low molecular weight CMC (Invention).

A latex of ethexyl lacrylate stabilized with ultralow molecular weight CMC was used in a PSA formulation. He PSA consisted of 60%, 70% or 80% latex, and therefore 20%, 30% or 40% of a glue resin dispersion. The resin dispersion was based on rosin ester (Tacolyn (r) 3179). In the adhesive composition, 0.6% by weight (wet) of Lumiten (mr) I-RA was also used.

In Table 4, the latex composition is provided; The latex used is a latex duplication mentioned in example 11. In Table 6, the PSA properties are presented. EXAMPLE 11 Water-based PSA using latex and stabilized latex with CMC of low p > molecular molecular (Invention).

• A latex of stabilized ethacrylate lacrylate with molecular weight CMC was employed in a PSA formulation.The PSA was composed of 60%, 70% and 80% latex, and consequently 20%, 30%. % and 40% resin dispersion of 5 glue The resin dispersion was based on modified hydrocarbon resin (HERCULES DC950330, with an elongation tip of 60 * C, marketed by HERCULES BV). used 0.6% by weight < \ / * (wet) of Lumi product in (mr) I-RA 10 In Table 4, the latex composition is provided, the latex used is the same as the latex used in the Example 11. The properties of the PSA are given in Table 6. This example showed in combination with examples 3.4, 15 and 1.5 16 the good stability of the latexes stabilized with Ambergum (mr) 3021 with various agents of glue TABLE 1 COMPOSITION AND CHARACTERISTICS OF LATEX EMPLOYEES Composition of monomerß Us or of stabilizer in latex latex Ex. 1 BA / MMA / MAA (85/10/5) Ambergu (R) 3021 (1% by weight of monomer) Ex. 2 BA / MMA / MAA (85/10 / 5) Ambergum (R) 3021 (1% by weight of monomer) 25 Ex. 3 BA / MMA / MAA (85/10/5) di ioct i lsulfosucc ina or (0.2%), "» noni If noletaxi lato sul pâmp , 9 EO (0.14%), noni 1 phenoletoxy lato sul fonado, 30 EO (0.28%) 5 Ex. 4 BA / MMA (95/5) Ambergum (R) 3021 (1% by weight of monomer) Ex. 5 BA / MAA (95/5) Ambergu (R) 3021 (1% by weight of monomer) ¿? ^., BA = buty lacr i lato 10 MMA = memetmecril to MAA - methacrylic acid The proportion of monomer is given by weight . All concentrations of stabilizers are active material by weight of monomer 15 TABLE 2 PSA PROPERTIES AT 23 ° C FORMULATIONS Stabilization Detachment Release of PE latex # < N / 25mm) of cardboard (N / 25mm) 20 Ex. 1 Ambergum (R) 1.9 PS ** 6 3021 (1%) Ex. 2 Ambergu (R) 19 PS 7 3021 (1%) Ex. A surfactants 22 PS 14 25 Ex. 3 Ambergum (R) 19 PS 4 -i. 3021. (1%) Ex. 4 Ambergu (R) 18 PS 5 3021 (1%) Ex. B commercial latex 20 3 Ex. C commercial latex 20 PS 5 Ex. D commercial latex 20 PS 4 Shear force P €. Loopback with steel, 1 kg PE (N / 25 m) (my tools) Ex. 1 > 10000 5 SS *** Ex. 2 > 1.0000 6 SS Ex. A 822 5 SS Ex. 3 2890 12 Ex. 4 3420 13 Ex. B > 2000 10 Ex. C 1000 12 E j. D 700 13 * PE means po iet i le or ** PS means pap.el stain *** SS stands for applicator bar TABLE 3 PROPERTIES OF PSAs AT 23 ° C USING DIFFERENT PEGAMENT AGENTS Dep. Performance Detachment PE glue (N / 25m) from cardboard (N / 25m) Ex. 3 Taeolyn (R) 3179 19 4 Ex. 5 Tacolyn (R) 64 16 4 Ex. 6 Tacolyn (R) 1070 8 3 5 Shear stress Locking steel loop, 1 kg (min) PE (N / 25 mm ) Ex. 3 2890 12 Ex. 5 > 1 000 7 «J-N Ex. 6 > 10000 5 10 TABLE 4 COMPOSITION OF CHARACTERISTICS OF THE LATEX EMPLOYEES Composition of Stabilizer Contained in monomers used in solids (%) latex Ex. 7 EHA / MAA (95/5) Ambergu (R) 3021 47.6 (1%) D ic: ie 1 ohe i 1 its 1-fosuccinate (1%) 20 TABLE 5 PSA PROPERTIES OF THE FORMULATIONS Stabilization Detachment Latex detachment to PE (N / 25mm) cardboard (N / 25mm) Ex. 7 Ambergu (R) 8 4 25 3021.

Ex. E Commercial 8 4 Ex. F Commercial 7 4 Shear force Loop glue with steel, 1 kg PE (N / 25 mm) (inutes) Ex. 7 1700 6 E. E 600 6 Ex. F 400 5 TABLE 6 PSA PROPERTIES OF SEVERAL FORMULATIONS PERCENTAGE IN DRY WEIGHT OF PSA GLUE SOURCE agent% Desing agent glue glue in PSA in PE (N / 25 m) Ex. 8 Tacolyn (mr) 2178 20 6 Ex. 8 Taealyn (r) 2178 30 8 Ex. 8 Tacolyn (r) 2178 40 8 Ex. 9 Hercules MGB 185 20 9 Ex. 9 Hercules MGB 185 30 25 Ex. 9 Hercules MGB 1.85 40 25 Ex. 10 Tacolyn (mr) 3179 20 8 Ex. 1.0 Tacolyn (mr) 3179 30 15 Ex. 10 Tacalyn (r) 3179 40 21 Ex. 1.1 Hercules (mr) DC950330 20 7 Ex. 11 Hercules (r) DC95033O 30 7 Ex. 11 Hercules (mr) DC950330 40 20 Detachment Shear stress Glue in cardboard (N / 25mm) in steel Ikg (min) PE loop (N / 25 ... m) E j. 8 6 1400 9 E j. 8 4 1700 6 E j. 8 4 1900 7 E j. 9"7 600 9 E Ex j .. 9 9 1 188 700 10 JN 9 15 800 1.2 E j 10 7 800 9 C - J * 10 8 400 9 E j 10 10 400 16 E Ejj .. 1 1.11 6 6 200 8 E j 1 1 4 300 9 E j 1 1 14 400 14 TABLE 7 System Pnl Pn2 foam Latex (1) Stabilizing monomer (nm) (2) (nm) (3) (mm) (4) Ex. 1 BA / MMA / MAA Ambergum (r) 430 350 16 (85/10/5) 3021 (1% weight / weight of manomer) Ex. 2 BA / MMA / MAA Ambergum (mr) 460 380 15 (85 / 10/5) 3021 (1% by weight / weight of mctnomer) Ex. 3 BA / MMA / MAA surfactants 1.1.0 see foot of 36 (81/10/5) table (5) DL. 322 based on BA surfactants < 100 1 0 35 Primal based on BA surfactants 520 550 65 PA 5560F Ex. 4 EHA / MMA 2% Ambergu 450 460 15 (95/5) (mr) 3021 + 1% d ic: ic 1ohex i 1su1 fosucc (0 % weight / weight of monomer) Acronal based on surfactants 400 2000 3 V205 EHA Acronal based on surfactants 500 1450 14 DS 3464 EHA 1) latexes marked copies were produced in Hercules A S. D Labsratary. DL 322 - Dow Prim l EP 5560F - Rohm and Haas Ac rna 1 V205 - Achanal DS 3464 BASF 2 - BASF (Pnl.) Particle size in accordance with that measured with a Joyce Laebl Disc Centrifuge before. " * Cut the latex, measured in nanometers. 3) (Pn2) Conform particle size as measured with a Joyce Loebl Disc Centrifuge after cutting the latex, which has been divided with iagua (1/1) for 5 minutes at high level with a Waring Mixer. 4) Height of the foam layer when the p > He proceeds in accordance with what is described under (3). 5) Latex coagulated when cut. * "Latexes were prepared in accordance with the" ~ 10 formulations in Table 1. Polymerizations. were carried out in a 2 liter glass reaction vessel coated with a thermocouple, a reflux condenser, a monomer inlet, an initiator inlet and a crescent shaped stirrer. The colloid, regulator and, Eventually, surfactant was dissolved simultaneously in the fill water. After resting during the night, , / "" * - the temperature was raised to SS ^ C by means of an Aryan bath. Then, 40% of the initiator was added for 30 seconds, after which the opmomer measurement and the rest of the initiator. The flow of the onomer ß increased up to 5% / 1.0 minutes. After 40 minutes, the monomer flow was increased to 60% / 10 minutes and maintained at this or during the time. of reaction. The monomer and the initiator were added during a 220 minute period with a piston pump and a peristaltic pump, respectively. The reaction temperature was maintained at 85 * C. After addition of the onomer and 90% of the initiator, the temperature was maintained at 85 ° C for an additional 1 hour. During this digestion time, the remaining 10% of the initiator was added. After this, the latexes were cooled to room temperature. EXAMPLE 12 This example clearly shows the combination of the higher p-mechanical stability together with a low tendency to "" * "10 the formation of esp in the case of the látexeß based on but i lacri lata stabilized with Ambergum (mr) in comparison with commercial latexes, used in this request TABLE 8 Component Ex. g) Ex.2 (.E j .A (g) (Ex. 8 (g) A Agguuaa 3 39988..55 3s-.98S.5v 410 500 Ambergum (mr) 1 16.6 16 .6 i 3 D-3021 (1) N HC03 1.6 1.6 1.6 2.0 2S208 1.5 1.5 1.5 2.0 20 BA 425 425 425 MMA 50 50 50 25 MAA 25 25 2-EHA 275 Disptoni .1 (mr) 0.6 t > SUS IC 875 (2), "Fenopon (r) 1.2 EP 1.00 (3) Fenopon (mr) 2.4 EP 120 (3) 5 Aerosol (mr) 5.2 A196 (4) 1) Marketed by Herculeß Incarporated. J '* "' 2) Marketed by Henkel Company. ~ 10 3) Marketed by Rho e Poulenc Comp.any 4) Marketed by Cytec Company. fifteen JO

Claims (14)

1. CLAIMS 1. A composition of "pressure sensitive" adhesives comprising an aqueous emulsion latex system comprising: a) a polymer of at least one selected ethylenically unsaturated monomer within the rump consisting of acrylic acid, methacrylic acid, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, acrylic esters, vinyl ethers, vinyl, vinylidene halides, N-vini ideal, ethylene, to C3 fae olefins or higher , allyl amines, allyl esters of saturated monocarboxylic acids and amides thereof, propylene, 1-butene, 1-pentene, 1-hexene, 1-dozen, allyl amines, allyl acetate, allyl propionate, lactate allyl, their amides, mixtures of the same, isomers of 1,3-butadiene, 1,3-pentadiene, 1,4-pentadiene, cyclopentadiene, hexadiene; and b) an effective amount to stabilize the latex system, of water soluble protective colloid with a p > that molecular lower than approximately 75,000, selected within the group that you conferred from carboxymethylcellulose and derivatives thereof, which has a carboxyl number of lower limit of substitution of approximately 0.07, hydroxet and cellulose, hydroxyethanol. Ethyl cellulose, methyl cellulose, methyl hydroxypropyl cellulose, hydropropyl cellulose, acid (pol i) acrylic acid and alkali metal salts thereof, derivatives of excipients, starch of sodium and other alkali metals, glue of water-soluble starch, gelatin, water-soluble alginates, casein, agar, natural and synthetic gums, alcohol (pol i) partial and fully hydrolyzed alcohol, polyacylamide, (psi) vinylhydroxypropyl, ether maleic anhydride (poly) ethyl vinyl, guar and derivatives thereof, gelatin, and casein.
2. 2. The pressure sensitive adhesive composition of claim 1, wherein at least one other adhesive ingredient is present.
3. 3. The pressure sensitive adhesive composition of claim 2, wherein at least one other adhesive ingredient is a glue agent.
4. 4. The composition of pressure sensitive adhesives of claim 3 wherein the detergent agent is selected from the group consisting of rosin esters, rosin acid, hydrochloride resin, resin dispersions based on rosin esters, resin dispersions based on rosin acid, resin dispersions based on hydrocarbon resin, and resin dispersions of the aforementioned resins emulsi fi ed with rosin soap in ve.z of conventional ßurfactants.
5. 5. The composition of piresion-sensitive adhesives of reiication 2, wherein at least one of the members selected from the group consisting of wetting agent, foam remover, thickener, solvent and preservative is also present.
6. 6. The composition of pressure sensitive adhesives of the rei indication 1, wherein the polymer has been imbedded by aqueous emulsion polymerization in the presence of the water-soluble protective colloid. The pressure sensitive adhesive composition of claim 1, further comprising about
7. 0. Approximately 4% surfactant by weight based on the total content of ethylenically unsaturated monomer.
8. 8. The pressure sensitive adhesive composition of claim 1, wherein the protective colloid has an upper molecular weight limit of about 75,000.
9. 9. The composition of pressure sensitive adhesives of the rei indication 1, wherein the protective colloid has an upper molecular weight limit of about 20,000.
10. 10. The composition of pressure-sensitive adhesives of the rei indication 1, wherein the protective colloid comprises a cellulose ether selected from the group consisting of hydrotymethylcellulose, ethylcellulose, carboxymethylcellulose it has a carboxyl number of lower limit of substitution of about 0.7, methylcelluloses, methylhydrocellulose, hydrocarboxylocellulose, and mixtures thereof.
11. 11. The composition of pressure sensitive adhesives of the reagent 1.0, wherein the cellulose ether comprises carboxymethylcellulose having a carboxyl number of 5 substitution of about 0.7-2.9.
12. 12. The composition of pressure-sensitive adhesives of the reagent 10, wherein the cellulose ether comprises carboxyme and hydroxyetheylcellulose with a molar substitution of - ^ hydroxyethyl between 0.2 and 2.0 and a 10 molar substitution of c rbox imet i between 0.1 and 1.0.
13. 13. The fielding of pressure-sensitive adhesives of the reagent 1, wherein at least one ethylenically unsaturated monomer comprises a member selected from the group consisting of acrylic acid, methacrylic acid, 15 butyl acrylate, methyl methacrylate, 2-ethylhexyl acrylate, acrylic esters, styrene, 1,3-butadiene isomers, 1,4-pentadiene, cyclopentadiene, hexadiene, and mixtures thereof.
14. 14. The composition of pressure sensitive adhesives of claim 1, wherein at least one electrically unsaturated manomene comprises a member selected from the group consisting of vinyl esters, vinyl ethers, vinyl, vinylidene halides, N -viny hydrocarbon, ethylene, C3 alpha olefins or greater, allyl amines, allyl esters of saturated monocarboxylic acids and amides thereof, and mixtures thereof; 1 15 r * -? O