WO2015161503A1

WO2015161503A1 - Polymer and aqueous composition for adhesive use thereof

Info

Publication number: WO2015161503A1
Application number: PCT/CN2014/076207
Authority: WO
Inventors: Kaibo Li; Zewei WANG; Xuan XIE
Original assignee: Henkel (China) Company Limited
Priority date: 2014-04-25
Filing date: 2014-04-25
Publication date: 2015-10-29

Abstract

A synthetic polymer obtainable by emulsion polymerization and water-based adhesive dispersions comprising the polymer are provided. The polymer and dispersion can be further formulated into adhesives for two kinds of adhesive applications: permanent bonding for varied paperboard and cardboard; or temporary bonding for on-off use on different paper substrates.

Description

POLYMER AND AQUEOUS COMPOSITION FOR ADHESIVE USE THEREOF

FIELD OF INVENTION

This invention relates to a specific synthetic polymer that can be obtained by emulsion polymerization, a water-based adhesive dispersion comprising this polymer, and an adhesive comprising the dispersion. The invention relates further to specific uses of the adhesive dispersion and adhesives. The polymer is particularly suitable for two kinds of adhesive applications: permanent bonding of varied paperboard and cardboard substrates; or temporary bonding for on-off use on different paper substrates.

BACKGROUND OF THE INVENTION

Currently, most polymer film laminated cardboard still needs to be side-sealed by aromatic hydrocarbon or alcohol containing adhesives, which cannot meet the environment-friendly requirements. Interest for environmental problems is today enhanced, and conventional organic solvents are more and more replaced by water to reduce the danger of environmental pollution, and enhance safety and health protection. Thus, it is highly demanded to develop aqueous compositions for adhesives having good high/low temperature performance and eliminating both, aromatic hydrocarbons (such as toluene, benzene, xylene, etc.) and alcohols (methanol, ethanol, etc.) from the final product.

The paper bonding adhesives that are commercially available in the market can be divided into three types: 1) adhesives for permanent bonding, to get bonding among different surfaces which cause deep substrate failure after separation, not only deformation but also significant fibre tear; 2) adhesives for temporary bonding, to get bonding between different surfaces which cause absolutely no substrate failure after separation, no deformation and fibre tear; 3) other adhesives that have no strict demand on performance, which may have good adhesion on the surface while could be peeled off with no/little substrate failure after separation, either deformation or fibre tear is acceptable.

Most permanent bonding adhesives are pressure sensitive adhesives (PSA) comprising rubber and/or solvent. Rubber provides elasticity and holding property, and solvent wets the interface to enhance the polymer colloid osmotic. Such combination provides good penetration on substrate surfaces, gives strong bonding during the drying process, and has a certain degree of flexibility to enhance creep resistance. However, the main drawbacks of this kind of paper bonding adhesive are high cost, lack of environmental friendliness, and poor adaptability. Thus, it is the objective of the present invention to develop a specific class of solvent-free water-borne adhesives providing satisfying bond strength on varied substrates like art paper, over print vanish (OPV) cardboard, polymer film laminated cardboard and metalized paperboard. As polymer films polyethylene terephthalate (PET), oriented Polypropylene (OPP), and polyethylene (PE) may be mentioned.

Adhesives used as disposable label glues need to show a moderate force to stick, while not showing breaking and remaining stickiness after ripping. Thus, it is a further objective of the present invention to develop an adhesive giving strong wet adhesion between two substrates, like art paper, kraft paper, offset paper, writing paper, thermal printing, glassine paper and release paper, while the dried adhesive neither exhibits fibre-tear (substrate failure) nor residual surface tack. Such adhesives would have a large market in future in disposable labelling, on-off sealing and some heat sealing use.

Many references deal with paper bonding adhesives:

US 2012213992 A1 describes a pressure-sensitive adhesive (PSA) polymer formed from (i) 50%-95% by weight of n-butyl acrylate, (ii) 1 %-20% by weight of ethyl acrylate, (iii) 1 %-20% by weight of vinyl acetate, (iv) 0.1 %-5% by weight of at least one ethylenically unsaturated acid or ethylenically unsaturated acid anhydride, and (v) 0% to 30% by weight of other ethylenically unsaturated compounds different from the monomers (i) to (iv). This PSA polymer can be used for producing self-adhesive articles, more particularly paper labels or film labels. Moreover, such kind of PSA is used as a dried film and shows good adhesion on paper and thermoplastic films (preferably corona-treated), while it is preferably removable after bonding or just causes little substrate failure if removed. Such PSA is not suitable for permanent bonding use.

Similar polymer and application can also be found in EP 2094799 A2. It describes removable pressure sensitive adhesive compositions and constructions that contain an emulsion acrylic pressure sensitive adhesive copolymer of a plurality of acrylic monomers and at least one polymerizable acid. The adhesive composition includes a pressure sensitive adhesive copolymer comprising a copolymer of (a) about 75% to about 90% by weight of one or more alkyl acrylates having from about 4 to about 12 carbon atoms in the alkyl group; (b) about 0.25% to about 5% by weight of one or more acid monomers; (c) about 10% to about 20% by weight of at least one hard monomer; (d) 0 to about 1 % by weight of at least one multifunctional crosslinking monomer. Further it is disclosed the labels comprising the adhesive composition, particularly removable polymeric labels for use on reusable containers. The adhesive cannot be used for permanent bonding, while can be used for temporary bonding even repeatable in some cases after dried, while it might cause fibre tear during laminating processes as the polymer might have strong wet adhesion. This kind of PSA itself is sticky and not suitable for on-off use.

US 201 1313093 A1 describes a microdomained aqueous emulsion polymer. The polymer comprises a first domain having a Tg of from -80 to -10°C, and comprising from 80 to 100 wt % of acrylic monomer; and a non-crosslinked second domain having a Tg of from 50 to 120°C, and comprising, as polymerized unit and based on the weight of the second domain, from 50 to 100 wt % of styrenic monomer; wherein the content of the second domain ranges from greater than 6 wt % to 30 wt % of the total weight of the first domain and the second domain. The polymer is suitable for applications including adhesives and binders, especially for pressure sensitive adhesives. Such polymer is using a two-stage process during polymerization and has micro-domain in it. The hard phase enhances the cohesion and the soft phase improves tack and initial adhesion. The combination of these phases leads to good balance in performance, which allowing use for label adhesive but not for permanent bonding.

From the above documents, it can be seen that pressure-sensitive adhesives are widely used for paper bonding. Acrylic pressure sensitive adhesive is especially popular in the market because of the sufficient tack on their own which does not require a tackifier, while they are all used after being dried, show good tack and adhesion on paper and films, show limited cohesion to cause substrate failure.

Thus, common PSA adhesives cannot be used directly for permanent bonding applications for its relatively low permanent adhesion, even if such PSA comprises tackifier and solvent, as they could not meet the demand to cause deep substrate failure.

It is highly demanded a polymer having a balance in initial adhesion and cohesion, being useful in various applications, as well as such aqueous compositions for adhesives having good high/low temperature performance and eliminating both aromatic hydrocarbons (such as toluene, benzene, xylene, etc.) and alcohols (methanol, ethanol, etc.) from the final product.

SUMMARY OF THE INVENTION

The present invention relates to a synthetic polymer comprising in polymerized form:

(i) 55-70% by weight of n-butyl acrylate,

(ii) 20-35% by weight of ethyl acrylate,

(iii) 5-15% by weight of comonomer (iii) selected from the group consisting of vinyl acetate, styrene, methyl methacrylate, and mixtures thereof,

(iv) 1.5-10% by weight of comonomer (iv) selected from the group consisting of methacrylic acid, acrylic acid, hydroxyethyl acrylate, hydroxypropyl acrylate, and mixtures thereof,

(v) 0.5-1.5% by weight of comonomer (v) selected from the group consisting of N-hydroxymethyl acrylamide, acetoacetoxyethyl methacrylate,

allylmethacrylate, and mixtures thereof.

Preferably, the polymer is obtained by emulsion polymerization.

The present invention further encompasses a water-based adhesive dispersion, comprising the polymer according to the present invention dispersed in water, and water-based adhesives comprising said dispersion.

Furthermore, the present invention encompasses two kinds of adhesive applications by further formulating the water-based adhesive dispersion: permanent bonding of varied paperboard and cardboard; or temporary bonding for on-off use on different paper substrates.

DETAILED DESCRIPTION OF THE INVENTION

In the following passages, the present invention is described in more detail. Each aspect so described may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous. In the context of the present invention, the terms used are to be construed in accordance with the following definitions, unless a context dictates otherwise.

As used herein, the singular forms "a", "an" and "the" include both singular and plural referents unless the context clearly dictates otherwise.

The terms "comprising", "comprises" and "comprised of" as used herein are synonymous with "including", "includes" or "containing", "contains", and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps.

The recitation of numerical end points includes all numbers and fractions subsumed within the respective ranges, as well as the recited end points.

All references cited in the present specification are hereby incorporated by reference in their entirety.

Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of the ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included to better appreciate the teaching of the present invention.

The present invention relates to a synthetic polymer obtainable by emulsion polymerization. The synthetic polymer is made using soft monomers, hard monomers, functional monomers and cross-linkers. Soft monomers are n-butyl acrylate and ethyl acrylate; hard monomers are selected from vinyl acetate, styrene and methyl methacrylate; functional comonomers include methacrylic acid, acrylic acid, hydroxyethyl acrylate, and hydroxy-propyl acrylate; cross-linkers include N-hydroxymethyl acrylamide, aceto-acetoxyethyl methacrylate, and allylmethacrylate.

The synthetic polymer according to the present invention has good adhesion properties, showing good bonding performance on different substrates and good adaptability on paperboard, cardboard and polymer films.

The polymer comprises in polymerized form:

(i) 55-70% by weight of n-butyl acrylate,

(ii) 20-35% by weight of ethyl acrylate, (iii) 5-15% by weight of comonomer (iii) selected from the group consisting of vinyl acetate, styrene, methyl methacrylate, and mixtures thereof,

allylmethacrylate, and mixtures thereof.

All given percentages of respective monomers refer to the total weight of the polymer.

Preferably, the polymer comprises in polymerized form 55-78% by weight, particular preferred 55-65% by weight, of n-butyl acrylate.

Ethyl acrylate is preferably used in an amount of 21-30% by weight, particular preferred 22-28% by weight.

Comonomer (iii) is preferably used in an amount of 5-12% by weight, particular preferred 6-10% by weight. If more than one comonomer (iii) is used, the given ranges refer to the total amount of comonomers (iii).

Comonomer (iv) is preferably used in an amount of 3-8% by weight, particular preferred 5-6% by weight. If more than one comonomer (iv) is used, the given ranges refer to the total amount of comonomers (iv).

Comonomer (v) is preferably used in an amount of 0.7-1.5% by weight, particular preferred 1-1.5% by weight. If more than one comonomer (v) is used, the given ranges refer to the total amount of comonomers (v).

Preferably, the polymer comprises in polymerized form:

(i) 55-65% by weight of n-butyl acrylate,

(ii) 22-28% by weight of ethyl acrylate,

(iii) 6-10% by weight of comonomer (iii) selected from the group consisting of vinyl acetate, styrene, methyl methacrylate, and mixtures thereof,

(iv) 5-6% by weight of comonomer (iv) selected from the group consisting of methacrylic acid, acrylic acid, hydroxyethyl acrylate, hydroxypropyl acrylate, and mixtures thereof, and (v) 1-1.5% by weight of comonomer (v) selected from the group consisting of N-hydroxymethyl acrylamide, acetoacetoxyethyl methacrylate,

allylmethacrylate, and mixtures thereof.

Preferably, the total amount of n-butyl acrylate, ethyl acrylate, comonomer (iii), comonomer (iv), and comonomer (v) is at least 95% by weight, particular preferred at least 99% by weight, and most preferred 100% by weight.

Preferably, the functional comonomer (v) is N-hydroxymethyl acrylamide.

N-hydroxymethyl acrylamide, with a chemical structure of CH2=CHCONHCH₂OH, is commercially available as a colorless or yellow 48 wt.% aqueous solution. It is also known as N-Methylolacrylamide and is a bi-functional monomer with both, a reactive vinyl and hydroxymethyl group. Thermoplastic polymers can be formed by copolymerization of N-methylolacrylamide with a variety of vinyl monomers by emulsion, solution and suspension polymerization techniques. The resulting products, which have pendant hydroxymethyl groups, can undergo cross-linking under moderate conditions. The uses of N-methylolacrylamide range from adhesives and binders in papermaking and textiles to a variety of surface coatings and resins for varnishes, films and sizing agents. It can be used in wet-strength and dry-strength agents for paper, in textile finishing agents for crease resistance, in antistatic agents, in dispersing agents, in cross-linking agents and in emulsion polymers.

One specific example of a suitable N-hydroxymethyl acrylamide to be used in the present invention is commercially available from Cytec/CYLINK NMA 48 or SNF FLOCRYL NMA 48.

The invention further relates to a water-based adhesive dispersion, comprising the polymer of the invention dispersed in water.

The water-based adhesive dispersion according to the invention preferably comprises at least 20%, preferably 20-60% by weight, particular preferred 30-50% by weight of the polymer, based on the total weight of the dispersion.

The water-based adhesive dispersion according to the present invention as such is already useful as an adhesive, for instance as a modified crosslinked pressure-sensitive adhesive composition. The units in the polymer derived from n-butyl acrylate and ethyl acrylate provide very good substrate penetration, which provides sensitive property. Units coming from vinyl acetate provide very strong bonding for paper substrates. Units coming from the functional monomer methyl methacrylate provide tack and surface adhesion. N-hydroxymethyl acrylamide derived units improve the cohesion and creep resistance. The water-based adhesive dispersion is useful as a modified pressure-sensitive adhesive which is equivalent to pressure-sensitive adhesives comprising rubber. Further, the water-based adhesive dispersion according to the invention is fast drying, providing improved surface wetting and strong bonding within a relatively short period of time. Such wet tack and substrate wetting property is promising for paper bonding.

The invention further relates to a permanent bonding formulation of the water-based adhesive comprising: 60-80% by weight of the water-based adhesive dispersion according to the invention, and 20-40% by weight of a wax emulsion, a tackifier emulsion, or mixtures thereof.

Preferably, the water-based adhesive comprises 8-15% by weight of at least one wax emulsion and 20-25% by weight of at least one tackifier emulsion.

For the purposes of this invention, the term "wax emulsion" is defined as a wax-containing water-based emulsion in which microscopic solid wax particles are suspended in an aqueous liquid which contains a concentration of at least one emulsifying agent which is sufficient to provide emulsion stability (i.e., the emulsion does not separate into its component parts upon standing), but is less than that concentration which would render the dried wax emulsion re-dispersible in water. Wax emulsion is introduced in this invention to enhance stability in the formulation and keep the liquid characteristics.

Wax is the name applied originally to naturally occurring esters of fatty acids and certain alcohols, but now applied to both natural and manufactured products resembling these esters. Petroleum waxes typically range from Ci₀H₃₈ to C₅oH₁₀2; paraffins going to C₃₃H₆8 followed by micros and petrolatums. Petroleum wax has the generic formula C_nH_2n+2- Though petroleum waxes are not referred to as "natural", they are derived from the decomposition of organic matter and contain 15% hydrogen and 85% carbon. Synthetic waxes are primarily derived from natural gas or ethylene.

Polyethylene waxes are made from ethylene produced from natural gas or by cracking petroleum naptha. Ethylene is then polymerized to produce waxes with various melting points, hardnesses and densities. Polyethylene molecular weights range from 500 to 3000 g/mol. Oxidized polyethylenes (PEs) are readily emulsifiable, whereas non-oxidized PEs largely are not. High-density polyethylenes (HDPE) have a great deal of crystallinity and their molecules are tightly packed. Melting points range from 85°C to 141 °C, and they are used in paints, textiles, coatings and polishes. Low-density polyethylenes (LDPE) display more toughness and exhibit better crystal formations. Densities are from 0.90 to 0.94 g/ml, and melting points range from 30°C to 141 °C. LDPEs are used to improve mar and abrasion resistance, lubricity, slip and anti-blocking.

Microcrystalline waxes have better adhesive and elastic qualities and are used extensively in hot melt adhesives as well as in the packaging, printing ink and many other industries. Microcrystalline wax is refined from petrolatum, which comes from bright stock oil. It typically contains 41-50 carbon atoms.

Suitable wax emulsions to be used in the present invention are preferably selected from the group consisting of polyethylene wax emulsions, modified polyethylene wax emulsions, high density polyethylene wax emulsions, modified high density polyethylene wax emulsions, and mixtures thereof.

High density refers to a density in the range of 0.941-0.960 g/ml. The modified polyethylene includes chlorinated polyethylene, chlorine polyethylene, cross-linked polyethylene and blends modified polyethylene.

Preferably, the wax emulsion is chosen from the commercially available products E842 (Keim-additec, Ultralube), Clariant Hordamer PE02, M.Land PE02 or Joule PE809/PE06, BYK Aquacer 1063/531 , E8801 C/8828/88226 (Keim-additec, Ultralube), Joule EP15/6302-6 or M.Land AE810, Michelman Michem Wax ME39235/ME91242, ans E612/620F (Keim-additec, Ultralube).

Particularly preferred, the wax emulsion to be used in the present invention is the polyethylene wax emulsion E842N, commercially available from Keim-Additec Surface GmbH, under the trade mark of Ultralube™, which has excellent temperature stability.

Tackifier emulsions are capable of being used for various aqueous adherence adhesives to achieve good adhesion performance. As with other adhesive technologies, waterborne polymer dispersion alone often cannot impart the optimum adhesion strength to the adhesive. Tackifier resins are often added for improving the adhesion to many different substrates. Waterborne tackifier resin dispersions are commonly used for PSA label, decal, or tape applications based on acrylic emulsion polymers or various types of natural or synthetic rubber latex. Waterborne tackifier resin dispersions have advantages like: improve specific adhesion especially to polyolefinic and paper substrates, improve flow and wetting out properties of the adhesives, provide an optimum balance between tack, adhesion and cohesion.

Suitable tackifier emulsions to be used in the present invention are preferably selected from the group consisting of rosin emulsions, rosin derivatives emulsions, terpene resin emulsions, and mixtures thereof.

Preferably, the tackifier resin emulsion is a rosin resin emulsion, wherein a ratio of the content of components with a molecular weight of at most 300 g/mol to the softening point of the rosin resin (the content (% by weight) of a component with a molecular weight of at most 300 g/mol/softening point (K)) is at most 0.004.

Preferably, the rosin resin used comprises rosins obtained by processing rosins by at least one kind of methods such as modification, hydrogenation, polymerization and esterification by adding alcohol or an epoxy compound, in addition to rosins such as gum rosin, toll oil rosin and wood rosin. Further, when the rosin resin is produced by using at least 2 kinds of respective steps such as modification, hydrogenation, polymerization and esterification by adding alcohol or an epoxy compound, their order is not specifically limited and may be decided by known methods. For example, after alcohol is added to the rosins to prepare ester, hydrogenation may be carried out and after the rosins are modified, polymerization may be carried out and then hydrogenation may be carried out.

Specific examples of suitable rosin emulsions to be used in the present invention are commercially available. Preferred rosin emulsions are selected from Snowtack SE 780G (Lawter Inc.), Arizona Aquatac XR-4316/4317/4343, Arizona Aquatac 6035/6085/9027, Arizona Aquatac E5375/E6180, Arizona Sylvalite RE/115/40, Arizona Sylvalite 105XL/80HP/100RC, Eastman Foralyn 90/110, and Eastman Foralyn 5020-F CG/WA-87, which have excellent adhesion stability.

The tackifier emulsion may also be a terpene resin emulsion. The term "terpene resins" refers to polymers of terpenes which are hydrocarbons of the general formula CioH₁₆ occurring in most essential oils and oleoresins of plants, and phenol-modified terpene resins. Terpene resins are derived from terpene feedstocks either from wood sources or from citrus fruit. They impart excellent, aggressive adhesion to almost all polymer types, including, natural rubber, EVA, APO, PE, SBR, SIS, SBS, and acrylics. Due to their very broad compatibility, they are sometimes called "universal tackifiers". Terpene resin use, however, is somewhat restricted due to their limited supply and high cost.

Suitable terpenes include alpha-pinene, beta-pinene, dipentene, limonene, myrcene, bornylene, camphene, and the like. These products occur as by-products of coking operations of petroleum refining and of paper manufacture.

A specific example of a suitable tackifier emulsion to be used in the present invention is commercially available as liquid terpene phenolic resin/ terpene phenolic resin emulsion from MULTIPLE PLUS CO LTD which has excellent adhesion stability.

The polymers according to the invention and the water-based adhesise dispersions comprising same, are obtainable by free-radical polymerization of the ethylenically unsaturated monomers. So they are prepared preferably by emulsion polymerization. Ionic and/or nonionic emulsifiers may be used in such a process, preferably in an amount of 0.3-0.5% by weight based on the total weight of all monomers to be polymerized. The emulsifier is preferably chosen from SDBS (sodium dodecyl benzene sulfonate), Rhodia DS-4, Rhodia DS-10, Rhodia A102, Rhodia RS610A25, BASF A3N, BASF A7N, DOW AE07, DOW AE03, and Rhodia TDA-70. Monomers and emulsifiers are preferably premixed in water to obtain a stable mixture. Water-soluble initiators (e.g. ammonium or alkali metal salts of peroxdisulfuric acid, hydrogen peroxide or organic peroxides) are used to start the polymerization. Na₂C0₃, NaHC0₃ or sodium acetate may be added during the polymerization process. Preferably, during the post-polymerization period and after ferrous sulfate solution is added, a redox solution system is introduced which is selected from (iso) ascorbic acid/ter-butyl hydroperoxide, formaldehyde, sodium/ter-butyl hydroperoxide, (iso)ascorbic acid/peroxysulphate, and other similar redox pairs. The polymerization preferable takes place at 78-85 °C . The obtained emulsion has preferable solids contents of 50-55% by weight.

The water-based adhesive dispersion or water-based adhesive may comprise further additives, e.g. different neutralizer, natural rubber, butylbenzene, carboxylic styrene butadiene latex or some solvent, e.g. alcohol, ketone, toluene, thinner.. However, since addition of solvent is disadvantageous from an environmental point of view, the total amount of solvent is preferably below 1 % by weight, particularly preferred below 0.1 % by weight based on the total weight of the water-based adhesive dispersion or water-based adhesive. In one embodiment the water-based adhesive dispersion or water-based adhesive is free from any solvent (water not being regarded as solvent in this context).

A further aspect of the invention is the use of the water-based adhesive dispersion according to the invention or the water-based adhesive comprising 60-80% by weight of the water-based adhesive dispersion, and 20-40% by weight of a wax emulsion, a tackifier emulsion, or mixtures thereof, to glue, coat or laminate a substrate selected from paper, art paper, over print varnish (OPV) cardboard, polyethylene terephthalate (PET) laminated cardboard, oriented polypropylene (OPP) laminated cardboard, polyethylene (PE) laminated cardboard, and aluminum coated paperboard.

The invention further relates to a temporary bonding formulation of the water-based adhesive comprising 30-50% by weight of the water-based adhesive dispersion according to the invention, and 50-70% by weight of a wax emulsion, a stearic acid or stearate emulsion, or mixtures thereof.

Preferably, the water-based adhesive comprises 35-50% by weight of the water-based adhesive dispersion according to the invention, and 50-65% by weight of a wax emulsion, a stearic acid or stearate emulsion or mixtures thereof.

In that case wax emulsions having a relatively high melting point (above 60 °C is preferred) and antiblocking properties, and also showing good film-forming ability and flexibility, are preferred. Preferably, the wax emulsion is selected from polyethylene wax emulsions, modified polyethylene wax emulsions, microcrystalline wax emulsions, and mixtures thereof.

Microcrystalline waxes are a type of wax produced by de-oiling petrolatum, as part of the petroleum refining process. In contrast to the more familiar paraffin wax, which contains mostly unbranched alkanes, microcrystalline wax contains a higher percentage of isoparaffinic (branched) hydrocarbons and naphthenic hydrocarbons. It is characterized by the fineness of its crystals in contrast to the larger crystal of paraffin wax. It consists of high molecular weight saturated aliphatic hydrocarbons. It is generally darker, more viscous, denser, tackier and more elastic than paraffin waxes, and has a higher molecular weight and melting point. The elastic and adhesive characteristics of microcrystalline waxes are related to the non-straight chain components that they contain. Typical microcrystalline wax crystal structure is small and thin, making them more flexible than paraffin wax. It is commonly used in cosmetic formulations.

Microcrystalline waxes when produced by wax refiners are typically produced to meet a number of ASTM specifications. These include congeal point (ASTM D938), needle penetration (D1321), color (ASTM D6045), and viscosity (ASTM D445). Microcrystalline waxes can generally be put into two categories: "laminating" grades and "hardening" grades. The laminating grades typically have a melting point of 60 - 80 °C and needle penetration of 25 or above. The hardening grades will range from about 80 - 93 °C, and have a needle penetration of 25 or below. Color in both grades can range from brown to white, depending on the degree of processing done at the refinery level.

Microcrystalline waxes are derived from the refining of the heavy distillates from lubricant oil production. This by-product then must be de-oiled at a wax refinery. Depending on the end use and desired specification, the product then may have its odor removed and color removed (which typically starts as a brown or dark yellow). This is usually done by means of a filtration method or by hydro-treating the wax material.

Wax emulsions used in this embodiment of the invention are preferably chosen from M. Land wax emulsion 8100, BASF WE-1/WE-6/WE-7, Joule wax emulsion 502, Joule 6202-6, PE0360/PE640, BYK Aquacer539, Michelman Michem 410/MD2000/D271 , 390/45FA and E623/E624/E521/E342/E522.

Preferably, the staric acid or stearate emulsion is selected from calcium stearate or magnesium stearate, being dispersed or emulsified to form stable emulsions.

Above adhesive emulsions are obtained by formulating at room temperature to get final products.

Other agents may be added to improve stability of the emulsion and meet different mechanical and rheological demands. For example oil based defoamer, e.g. paraffin oil, mineral oil, or silicone based defoamer may be added in an amount of 0.1-0.6%wt based on the total weight of the water-based adhesive dispersion or water based adhesive. Such defoamer may be selected from Evonik Tego Antifoam 2291/D2315/Antifoam 1488/Fomax 4-94, BASF Cognis Foamaster 8034A/Foam Star ED2522(SE2), Hi-Mar DFC-21 , Rhodia BL 225 etc. Another additive are cellulosic thickeners and polyacrylate thickeners. If present, the preferred amount is 0-2%wt based on the total weight of the water-based adhesive dispersion or water based adhesive. Preferably, these thickeners are chosen from hydroxymethyl cellulose (HEA), hydroxyethyl cellulose (CMC), BASF VISCALEX AT88, OMG Borch Gel ALA, et al. Further examples of additives are biocides and wetting agents. As preferred biocide ACTICIDE MBS may be mentioned. Such biocides are prferably used in an amount up to 0.1 % by weight based on the total weight of the water-based adhesive dispersion or water based adhesive. Preferred wetting agents are chosen from Cytec AEROSOL OT 75, BYK Dynwet 800, Air Products and Chemicals Surfynol 140E/420, and Evonik TEGO Surten W 1 11 , and preferably added in an amount of 0-0.5% by weight based on the total weight of the water-based adhesive dispersion or water based adhesive to get good wetting behavior.

A further aspect of the invention is the use of the water-based adhesive dispersion according to the invention or the water-based adhesive comprising 30-50% by weight of the water-based adhesive dispersion according to the invention, and 50-70% by weight of a wax emulsion, a stearic acid or stearate emulsion, or mixtures thereof , to glue, coat or laminate a substrate selected from art paper, kraft paper, offset paper, writing paper, thermal printing paper, glassine paper, and release paper.

EXAMPLES

Synthetic Emulsion

In the synthesis examples, abbreviations are used as follows:

Dl W: deionized water

BA: n-butyl acrylate

EA: ethyl acrylate

MA: methyl acrylate

VAc: vinyl acetate

VeoVa: vinyl ester of versatic acid

St: styrene

MMA: methyl methacrylate

MAA: methacrylic acid

AA: acrylic acid

HEA: hydroxyethyl acrylate

HPA: hydroxy-propyl acrylate

NMA: N-hydroxymethyl acrylamide

NMA-lf: N-hydroxymethyl acrylamide-low formaldehyde

AAEM: acetoacetoxyethyl methacrylate

ALMA: allylmethacrylate

β-CEA: β-carboxyethyl acrylates (Rhodia SIPOMER)

DAAM: diacetoneacrylamide

ADH: adipic dihydrazide

Na₂C0₃: sodium carbonate

APS: ammonium persulfate

tBHP: tert-butyl hydroperoxide

IAA: iso-ascorbic acid

DS-4: sodium dodecyl benzene sulfonate (SDBS)

In the text and evaluation examples, abbreviations are used as follows:

OPV: over print vanish cardboard

PET: polyethylene terephthalate film laminated cardboard

PE: polyethylene film laminated cardboard

OPP: oriented Polypropylene film laminated cardboard

AL: aluminum coated paperboard

AP: art paper

KP: kraft paper

OP: offset paper WP: writing paper

TP: thermal printing paper

GP: glassine paper

RP: release paper

SF: substrate failure

Example 1 (K 1)

A pre-emulsion was prepared by 300 g of Dl W, 17.5 g of DS-4 (22.5%, w/w), 655 g of BA, 300 g of EA, 91 g of VAc, 60 g of MAA, 15 g of NMA (48%, w/w) and kept stirring till stable. Dl W 320 g, Na₂C0₃ 0.75 g, DS-4 0.5 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 3 g of APS and 1.55 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2079 g and solid content is 53.8%.

Example 2 (K 2)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 613 g of BA, 280.8 g of EA, 168.4 g of VAc, 18.8 g of MAA, 14 g of NMA (48%, w/w) and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 3 (D 1)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 690.2 g of BA.148 g of EA, 92.7 g of MA, 92.9 g of VAc, 54.8 g of MAA, 16.4 g of ALMA and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 4 (D 2)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 836.8 g of BA, 41.6 g of EA, 107.5 g of MMA, 64.5 g of VeoVa, 38.9 g of MAA, 5.7 g of NMA (48%, w/w) and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W. The feeding time is roughly 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 5 (D 3)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 643.3 g of BA, 204.1 g of EA, 54.6 g of St, 35.8 g of MMA, 127.6 g of VeoVa, 15.38 g of MAA, 14.2 g of NMA (48%, w/w) and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%. Example 6 (O 1)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 718.2 g of BA, 214.4 g of EA, 96.5 g of VAc, 64.3 g of MAA, 1.6 g of ALMA and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together , a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 7 (O 2)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 390.7 g of BA, 439.5 g of EA, 138.8 g of VAc, 109.5 g of MAA, 16.4 g of NMA (48%, w/w) and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W. The feeding time is roughly 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 8 (O 3)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 281.6 g of BA, 280 g of EA, 383.3 g of VAc, 59.5 g of VeoVa, 70.5 g of MAA, 20.1 g of NMA (48%, w/w) and kept stirring till stable. Dl W 312.5 g, Na2C03 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 9 (L 1)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 767.6 g of BA, 216.8 g of EA, 73.4 g of VAc, 25.2 g of MAA, 12 g of NMA(48%, w/w) and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 10 (L 2)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 604.4 g of BA, 221.2 g of EA, 167.5 g of VAc, 96.4 g of MAA, 5.5 g of NMA (48%, w/w) and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W. The feeding time is roughly 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 11 (L 3)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 615.4 g of BA, 236.5 g of EA, 77.7 g of VAc, 55.4 g of MMA, 96.4 g of MAA, 18.6 g of NMA (48%, w/w) and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 12 (L 4)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 605.5 g of BA, 291.3 g of EA, 51.5 g of VAc, 26.3 g of MMA, 1 13.9 g of MAA, 6.6 g of NMA (48%, w/w) and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 13 (L 5)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 600.1 g of BA, 395.3 g of EA, 69 g of VAc, 25.2 g of MAA, 5.5 g of NMA(48%, w/w) and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W. The feeding time is roughly 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 14(L 6)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 650.4 g of BA, 250 g of EA, 70.1 g of VAc, 94.2 g of MMA, 15 g of MAA, 15.3 g of NMA (48%, w/w) and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 15 (I 1)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 667.2 g of BA, 273.9 g of EA, 65.2 g of St, 50.7 g of MAA, 32.6 g of HEA, 5.5 g of NMA (48%, w/w) and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 16 (I 2)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 675.9 g of BA, 289.6 g of EA, 54.1 g of VAc, 30.9 g of MMA, 29.1 g of AA, 15.3 g of NMA (48%, w/w) and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%. Example 17 (I 3)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 679 g of BA, 240.6 g of EA, 63.2 g of VAc, 9.9 g of MAA, 87.9 g of HEA, 14.5 g of AAEM and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 18 (I 4)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 653.5 g of BA, 266.3 g of EA, 77 g of VAc, 13.2 g of MM A, 1 1.4 g of AA, 58.4g of HPA, 15.2 g of NMA (48%, w/w) and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 19 (I 5)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 673.5 g of BA, 288.2 g of EA, 53.9 g of VAc, 30.8 g of MMA, 33.3 g of AA, 15.3 g of NMA (48%, w/w) and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 20 (X 1)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 720.3 g of BA, 240.1 g of EA, 98.2 g of VAc, 24 g of MAA, 12.4 g of ALMA and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 21 (X 2)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 636.5 g of BA, 293 g of EA, 91.1 g of VAc, 58.6 g of MAA, 15.8 g of AAEM and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together , a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 22 (X 3)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 704.9 g of BA, 249.2 g of EA, 83.3 g of VAc, 47 g of MAA, 10.6 g of ALMA and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 23 (X 4)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 639.8 g of BA, 293 g of EA, 88.9 g of VAc, 58.6 g of MAA, 14.7 g of β-CEA and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 24 (X 5)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 626 g of BA, 258.2 g of EA, 134.9 g of VAc, 59.5 g of MAA, 11 g of DAAM and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, add 5.5 g of ADH in 20 g of DIW, which was prepared before use with warm water, hold for 1 h. The reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Example 25 (X 6)

A pre-emulsion was prepared by 293 g of Dl W, 17.1 g of DS-4 (22.5%, w/w), 639.8 g of BA, 293 g of EA, 88.9 g of VAc, 58.6 g of MAA, 14.7 g of NMA-lf (48%, w/w) and kept stirring till stable. Dl W 312.5 g, Na₂C0₃ 0.73 g, DS-4 0.49 g were mixed in reactor and heated to 85 °C. 4.81 g of APS was dissolved in 20 g of Dl W and added into the reactor, then the pre-emulsion of monomers is added by continuous feeding for 1.5-2 h. Together, a solution of 2.93 g of APS and 1.51 g of Na₂C0₃ in 90 g of Dl W is fed by 2 h-2.5 h. After pre-emulsion was fed up, the reactor was hold at 85 °C for 15-30 min. Then, the reactor was cooled. When the temperature reached 70 °C, 2.0 g of tBHP in 40 g of Dl W and 1.8 g of IAA in another 40 g of Dl W were added separately by 1 h. When cooling below 40 °C, the reaction mixture was neutralized by ammonia solution to pH 8-8.5. The total weight is 2030 g and solid content is 53.7%.

Permanent Bonding Formulation

Example 26 (P 1)

740 g of the emulsion in Example 1 , 260 g of rosin emulsion were mixed at room temperature and further formulated with defoamer, antiseptic and thickener.

Example 27 (P 1)

The amount were same as Example 26, Example 1 could be changed into Example 3, Example 6, Example 13, Example 15, Example 21 or Example 22.

Example 28 (P 2)

800 g of the emulsion in Example 15, 200 g of rosin emulsion were mixed in room temperature and further formulated with defoamer, antiseptic and thickener.

Example 29 (P 3)

650 g of the emulsion in Example 21 , 350 g of rosin emulsion were mixed in room temperature and further formulated with defoamer, antiseptic and thickener.

Example 30 (P 4)

500 g of the emulsion in Example 13, 500 g of rosin emulsion were mixed in room temperature and further formulated with defoamer, antiseptic and thickener.

Example 31 (P 5)

670 g of the emulsion in Example 1 , 230 g of rosin emulsion and 100 g of wax emulsion were mixed in room temperature and further formulated with defoamer, antiseptic and thickener.

Example 32 (P 5)

The amount were same as Example 31 , Example 1 could be changed into Example 2, Example 3, Example 6, Example 9, Example 13, Example 15, Example 17 or Example 21.

Example 33 (P 6) 720 g of the emulsion in Example 15, 200 g of rosin emulsion and 80 g of wax emulsion were mixed in room temperature and further formulated with defoamer, antiseptic and thickener.

Example 34 (P 7)

650 g of the emulsion in Example 20, 250 g of rosin emulsion and 100 g of wax emulsion were mixed in room temperature and further formulated with defoamer, antiseptic and thickener.

Example 35 (P 8)

650 g of the emulsion in Example 13, 200 g of rosin emulsion and 150 g of wax emulsion were mixed in room temperature and further formulated with defoamer, antiseptic and thickener.

Rosin emulsion is preferred chosen in SE 780G (BASF, Snowtack), Arizona Aquatac XR-4316/4317/4343, Aquatac 6035/6085/9027, Arizona Aquatac E5375/E6180, Arizona Sylvalite RE/115/40, Arizona Sylvalite 105XL/80HP/100RC, Eastman Foralyn 90/1 10, Eastman Foralyn 5020-F CG/WA-87.

Wax emulsion is preferred chosen in E842 (Keim-additec, Ultralube) , Clariant Hordamer PE02, M.Land PE02 or Joule PE809/PE06, BYK Aquacer 1063/531 , E8801 C/8828/88226(Keim-additec, Ultralube), Joule EP15/6302-6 or M.Land AE810, Michelman Michem Wax ME39235/ME91242, E612/620F(Keim-additec, Ultralube).

Temporary Bonding Formulation

In the formulation part, stearic acid emulsion with a solid content of 30%wt, calcium stearate emulsion with a solid content of 50%wt and magnesium stearate emulsion with a solid content of 35%wt are used, the solid ratio should be recalculated if solid content changes.

Example 36 (T 1)

300 g of the emulsion in Example 15, 700 g of stearic acid emulsion were mixed in room temperature and further formulated with defoamer, antiseptic and thickener.

Example 37 (T 2)

300 g of the emulsion in Example 16, 700 g of calcium stearate emulsion were mixed in room temperature and further formulated with defoamer, antiseptic and thickener. Example 38 (T 3)

300 g of the emulsion in Example 21 , 700 g of wax emulsion were mixed in room temperature and further formulated with defoamer, antiseptic and thickener.

Example 39 (T 4)

500 g of the emulsion in Example 1 , 500 g of stearic acid emulsion were mixed in room temperature and further formulated with defoamer, antiseptic and thickener.

Example 40 (T 5)

500 g of the emulsion in Example 20, 500 g of magnesium stearate emulsion were mixed in room temperature and further formulated with defoamer, antiseptic and thickener.

Example 41 (T 6)

500 g of the emulsion in Example 13, 500 g of wax emulsion were mixed in room temperature and further formulated with defoamer, antiseptic and thickener.

Example 42(T 7)

420 g of the emulsion in Example 1 , 580 g of wax emulsion were mixed in room temperature and further formulated with defoamer, antiseptic and thickener.

Example 43(T 8)

500 g of the emulsion in Example 1 , 400 g of stearic acid emulsion and 100 g of wax emulsion were mixed in room temperature and further formulated with defoamer, antiseptic and thickener.

Example 44 (T 8)

The amount were same as Example 43, Example 1 could be changed into Example 2, Example 3, Example 6, Example 9, Example 13, Example 15, Example 17 or Example 21.

Example 45 (T 9)

300 g of the emulsion in Example 16, 500 g of stearic acid emulsion and 300 g of calcium stearate emulsion were mixed in room temperature and further formulated with defoamer, antiseptic and thickener.

Example 46 (T 10) 300 g of the emulsion in Example 15, 400 g of magnesium stearate emulsion and 300 g of wax emulsion were mixed in room temperature and further formulated with defoamer, antiseptic and thickener.

Example 47 (T 1 1)

450 g of the emulsion in Example 22, 350 g of calcium stearate emulsion and 200 g of wax emulsion were mixed in room temperature and further formulated with defoamer, antiseptic and thickener.

Wax emulsion is preferred chosen in M.Land wax emulsion 8100, BASF WE-1/WE-6/WE-7, Joule wax emulsion 502, Joule 6202-6_^ PE0360/PE640, BYK Aquacer539, Michelman Michem 410/MD2000/D271 , 390/45FA or E623/E624/E521 /E342/E522.

The emulsion is then further mixing with other emulsions at room temperature to get stable emulsion and meet different demands of customers. Oil based / silicone defoamer with an amount of 0.3%wt based on emulsion can be selected from Evonik Tego Antifoam 2291/D2315/Antifoam 1488/Fomax 4-94, BASF Cognis Foamaster 8034A/Foam Star ED2522(SE2), Hi-Mar DFC-21 , Rhodia BL 225 etc. Cellulosic thickener/Polyacrylate thickener with an amount of 0.2 % wt-2 % wt based on emulsion can be chosen from hydroxymethyl cellulose(HEA), hydroxyethyl cellulose (CMC), BASF VISCALEX AT88, OMG Borch Gel ALA, et al. ACTICIDE MBS is used as biocide with 0.1 %. Wetting agent (0.1 % wt-0.5 % wt) is chosen from Cytec AEROSOL OT 75, Cytec WA300, BYK Dynwet 800, Air Products and Chemicals Surfynol 140E/420, Evonik TEGO Surten W 11 1 etc.

Permanent Bonding Test

Example 48

Performance testing on different substrates (Surface energy from 30-40 Dyne) is conducted. Using the surface of paperboard or cardboard, including art paper (AP), over print vanish (OPV) cardboard, plastic film laminated cardboard (PET, OPP, PE) and aluminium coated paperboard (AL) as one side, white cardboard as another side. Stick both sides together using 0.4 mm blade to control the glue amount. The samples are pressed by 1 kg weights under 25°C , 65%RH for 6h and left for 12h. Then after staying for 24h in different environment for room temperature, -20°C and 60°C , test the adhesion by slow peel test (0.5mm/s) and quick flick test (Instant finger flick with a distance of 1 cm). Total glue area is 1 cm*1 cm, substrate failure (SF) is calculated by the formulation: _{SF =} The damaged area _{χ 100%}

Total gluing area

The result represents the average of peel test and flick test, each of which has 3 samples.

Performance on different substrates using pure synthetic emulsion

("— " means no substrate failure appeared)

Performance on different substrates using formulation synthetic emulsion with rosin (P 1 Formulation according to Example 26) With Substrate Failure(%)

tackifier AP OPV PET PE OPP AL

K1 100 80 100 90 70 100

D1 100 10 40 30 — 30

01 100 90 80 70 30 40

L5 100 40 85 55 40 70

11 100 50 80 60 55 70

X2 100 40 50 65 45 70

X3 100 40 40 50 20 70

("— " means no substrate failure appeared)

Performance on different substrates using formulation synthetic emulsion with rosin and wax (P 5 Formulation according to Example 31 ,32)

("— " means no substrate failure appeared)

As the results for different formulations show, it was found that the pure synthetic emulsion has good performance on art paper and OPV cardboard, adding rosin could help with the adhesion on plastic film and aluminum film while has no good to OPV substrates. The full formulation with rosin and wax has greatly improved the adhesion on plastic film and aluminum film.

This solvent-free aqueous emulsion could be a substitute for solvent-contain adhesive in box folding/making, paper bag making to meet the environment-friendly requirement in future, it eliminates both aromatic hydrocarbons (such as toluene, benzene, xylene, etc.) and alcohols (methanol, ethanol, etc.) from final product and keeps high/low temperature performance. Temporary Bonding Test

Example 49

Use winding bar (5 μηι, 12 μηι, 25 μηι, 50 μηι) to get thin film coating (chosen form Example 21-38) on the A4 printing paper (Double A, KHAN-NA, Double A (1991) Public Co., Ltd, Thailand), then another piece of paper was covered on and laminated using smooth metal bar. The samples were dried naturally overnight (>8 hours) under 5kg/100cm² pressure. Then cut into slips with width of 1.0 inch, the length should be larger than 10 inch. Then peeling strength was tested using Texture Analyser under a test speed of 300mm/min.After peeling off, check if any substrate failure happens and the surface tack and touch on both sides. Substrate failure (SF) is calculated by the

Peeling Strength Test

Other qualitative test were done to coat 12 μηι wet glue on art paper, kraft paper, offset paper, writing paper, thermal printing, glassine paper and re-lease paper to see the adaptability on different substrates, to see if it could give strong wet adhesion between and would cause fibre-tear (substrate failure) and residual surface tack or not. Qualitative Test different substrates based on Example 43&44 (According formulation T 8)

("Y" means fibre-tear or residual surface tack appeared; "— " means no fibre-tear nor residual surface tack appeared)

Glue has been tested between different substrates, like art paper, kraft paper, offset paper, writing paper, thermal printing, glassine paper and release paper. Some substrate failure occurred and some has no tack left with smooth touch on surface after peeling. Proper formulation of water-based adhesive gave strong wet adhesion between two substrates, while after dried, peeling off would cause neither fibre-tear (substrate failure) nor residual surface tack. Such kind of on-off use could make sense in the applications of disposable labelling, on-off sealing and some heat sealing use.

Claims

1. A polymer, comprising in polymerized form:

(i) 55-70% by weight of n-butyl acrylate,

(ii) 20-35% by weight of ethyl acrylate,

allylmethacrylate, and mixtures thereof.

2. The polymer according to claim 1 , comprising in polymerized form:

(i) 55-65% by weight of n-butyl acrylate,

(ii) 22-28% by weight of ethyl acrylate,

(iv) 5-6% by weight of comonomer (iv) selected from the group consisting of methacrylic acid, acrylic acid, hydroxyethyl acrylate, hydroxypropyl acrylate, and mixtures thereof,

(v) 1-1.5% by weight of comonomer (v) selected from the group consisting of N-hydroxymethyl acrylamide, acetoacetoxyethyl methacrylate,

allylmethacrylate, and mixtures thereof.

3. The polymer according to at least one of claims 1 to 2, wherein the total amount of n-butyl acrylate, ethyl acrylate, comonomer (iii), comonomer (iv), and comonomer (v) is 100% by weight.

4. The polymer according to at least one of claims 1 to 3, wherein comonomer (v) is N-hydroxymethyl acrylamide.

5. A water-based adhesive dispersion, comprising the polymer according to at least one of the preceding claims dispersed in water.

6. The water-based adhesive dispersion according to claim 5, wherein the dispersion comprises at least 20% by weight of the polymer according to at least one of claims 1 to 4, based on the total weight of the dispersion.

7. A water-based adhesive, comprising:

(i) 60-80% by weight of the water-based adhesive dispersion according to at least one of claims 5 and 6 and

(ii) 20-40% by weight of a wax emulsion, a tackifier emulsion, or mixtures thereof.

8. The water-based adhesive according to claim 7, comprising 8-15% by weight of at least one wax emulsion and 20-25% by weight of at least one tackifier emulsion.

9. The water-based adhesive according to at least one of claims 7 and 8, wherein the wax emulsion is selected from the group consisting of polyethylene wax emulsions, modified polyethylene wax emulsions, high density polyethylene wax emulsions, modified high density polyethylene wax emulsions, and mixtures thereof.

10. The water-based adhesive according to at least one of the claim 7 to 9, wherein the tackifier emulsion is selected from the group consisting of rosin emulsions, rosin derivatives emulsions, terpene resin emulsions, and mixtures thereof.

1 1. A water-based adhesive, comprising:

(i) 30-50% by weight of the water-based adhesive dispersion according to at least one of claims 5 and 6, and

(ii) 50-70% by weight of a wax emulsion, a stearic acid or stearate emulsion, or mixtures thereof.

12. The water-based adhesive according to claim 1 1 , comprising:

(i) 35-50% by weight of the water-based adhesive dispersion according to at least one of claims 5 and 6, and

(ii) 50-65% by weight of a wax emulsion, a stearic acid or stearate emulsion or mixtures thereof.

13. The water-based adhesive according to at least one of claims 1 1 and 12, wherein the wax emulsion is selected from the group consisting of polyethylene wax emulsions, modified polyethylene wax emulsions, microcrystalline wax emulsions, and mixtures thereof.

14. Use of the water-based adhesive dispersion according to at least one of claims 5 to 6 or the water-based adhesive according to at least one of claims 7 to 10 to glue, coat or laminate a substrate selected from paper, art paper, over print varnish (OPV) cardboard, polyethylene terephthalate (PET) laminated cardboard, oriented polypropylene (OPP) laminated cardboard, polyethylene (PE) laminated cardboard, and metalized paperboard.

15. Use of the water-based adhesive dispersion according to at least one of claims 5 to 6 or the water-based adhesive according to at least one of claims 11 to 13 to glue, coat or laminate a substrate selected from art paper, kraft paper, offset paper, writing paper, thermal printing paper, glassine paper, and release paper.