JPS6189217A - Polymer latex having pendant reactive group and pendant oxazoline group - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to curable polymer latexes, and more particularly to self-curing polymer latexes.

A variety of self-curing latexes are well known in the art. Examples include capoxylated latexes such as acrylic acid/styrene/butadiene terpolymers and melamine
It is known in the art that formaldehyde resins or blends with urea-formaldehyde resins are self-curing, ie they form curable compositions that cure at elevated temperatures.

Other self-curing latex systems use carboxylated latexes that are also bonded with polyvalent cations or cationic polymers. Such latexes have the disadvantage of being pH-dependent and very sensitive to water, solvents and other chemicals.

It is therefore highly desirable to provide a polymer latex that is self-curing without the formation of by-products and which upon curing forms a film or adhesive with excellent physical properties and improved resistance to water and organic solvents. .

It would also be desirable to provide a method for making polymers containing both pendant acid groups and pendant oxazoliff groups.

The present invention provides such polymers and methods. In one aspect, the present invention provides a curable latex composition comprising a group of discrete polymer particles, the polymer portion of which contains a co-reactive monomer containing a pendant group capable of reacting with (α) an oxazolyl group to form a covalent bond. and (b) general formula [
However, R1 is an acyclic organic group having addition polymerizable unsaturation; each R1 is independently hydrogen, halogen, or an inert substituted organic group. & is 1 or 2] and (C) at least one other addition-polymerizable monomer that does not contain a co-reactive group or an oxazolif group (however, it contains an oxazoline represented by A curable latex composition characterized in that the reactive groups are pendant.

- plane with (α) a pendant co-reactive group and (b)! Both pendant oxazoline groups are present in the same latex particle in at least a portion of the latex particles. In a slightly different embodiment, the (CL) pendant reactive groups are present on one portion of the latex particles and (b) the pendant ochinacillin groups are present on a second, separate portion of the latex particles.

In another aspect, the invention provides a method for producing a latex comprising a discrete population of particles containing both pendant co-reactive groups and pendant oxazolif groups, comprising the steps of: (a) abrasive weak acid groups; and at least one addition-polymerizable monomer copolymerizable with the weak acid monomer at a pH in the range of 1 to 6. A latex containing particles is prepared and then the PM of the latex is added such that the polymerizable oxazoline does not substantially react or hydrolyze under conditions suitable for its polymerization [K adjusted;
(C) To this latex, (υ general formula [where R1 is an acyclic organic group having addition polymerizable unsaturation; is 1 or 2] and (2) at least one other monomer that does not contain any pendant co-reactive groups or pendant oxazoliff groups. , and (4) polymerizing the monomer mixture under conditions such that the second monomer mixture is polymerized within or around the suspended co-reactive weak acid group-containing polymer particles. Method: Provides.

Surprisingly, the latex of the present invention exhibits excellent tensile strength and elongation upon conversion and curing, as well as excellent water and bath medium resistance. Such latexes are useful in a variety of applications including films, coatings, adhesives, nonwoven binders, and the like.

The latex composition of the present invention ri(α) is a group of separated polymer particles containing both a pendant oxazoline group and a pendant co-reactive weak acid group and /17'c (at least a portion of the b number group is a pendant oxazoline group). and a second separate portion of the particles comprises a group of separate polymer particles containing pendant co-reactive groups.

The oxazoline used here is represented by the following general formula.

However, R' Fi is an acyclic M unit number with addition polymerizable unsaturation: each OR1 is independently hydrogen, halogen, or an inert rIt substituted organic group): and 1 is 1 or 2
It is. Preferably, R1 is H, C-C-CB" is hydrogen or an alkyl group. Most preferably it is an RIFi isoproynyl group. Each R1 is preferably hydrogen or an alkyl group, and most preferably a hydrogen group. , n is preferably 1
It is. Most preferably the oxazoline is 2-improbenitv-2-oxazoline.

The oxazoline-modified polymer also includes a folding unit derived from at least 1 m monomer that is not an oxazoline and is copolymerizable with the oxazoline. It is. Suitable monomers include, for example, monovinyl aromatics, alkenes, esters of α,β-unsaturated carboxylic acids, carboxylic acid esters containing addition polymerizable unsaturation in the ester group, halogenated alkenes, and acyclic conjugated dienes. . Small amounts of cross-linking monomers such as divinylbenzene may also be used.

1 Monovinyl Fragrance Exhibition used here is Inuyama AMC
- (R is hydrogen or lower alkyl, e.g., 1 to 4 carbon atoms, also qualkyl) group contains an aromatic nucleus containing 6 to 10 carbon atoms (including those in which the aromatic nucleus is substituted with alkyl or halogen) ) includes monomers bonded to Typical of these monomers are styrene; α-methylstyrene: ortho;
Meta- and para-methylstyrene: ortho-, meta-
and para-etherstyrene; o, p-/methylstyrene; o, p-diethylstyrene H to butylstyrene: p-chlorostyrene: p-bromostyrene wasp
-di/rorostele 7m1) up-dipromostyrene: vinylnaphthalene; various vinyl (alkylnaphthalenes @
) and vinyl (halonaphthalene type 7) and copolymerizable mixtures thereof. Styrene and vinyltoluene are preferred in consideration of price, availability, ease of use, etc., and styrene is particularly preferred as the heptanovinyl aromatic monomer.

Suitable alkenes for use in the present invention include monounsaturated aliphatic organic compounds such as ethylene/, leu and in-propylene/, various butenes, (butenes and hexenes and various substituted compounds inert to polymerization). Mention may be made of alkenes containing the group. Unsubstituted Cm alkenes are preferred, and unsubstituted "Ct-04" alkenes are most preferred.

Esters of α,β-ethylenically unsaturated carboxylic acids useful in the present invention include soft acrylates whose homopolymers have a glass transition point (CTy) of less than about 25°C, such as benzyl acrylate, butyl acrylate, secondary Butyl acrylate, cyclohexyl acrylate, dodecyl acrylate, ethyl acrylate, 2-ethylbutyl acrylate, 2-ethylhexyl acrylate, heptyl acrylate, hexyl acrylate,
Inbutyl acrylate, isopropyl acrylate,
Examples include methyl acrylate and propyl acrylate. Tf whose homopolymer is about 25°C or higher
hard acrylates such as 4-biphenyl acrylate and butyl acrylate; and soft methacrylates such as secondary butyl methacrylate, ethyl methacrylate, isobutyl methacrylate, inbutyl methacrylate, isopropyl methacrylate, methyl methacrylate and propyl methacrylate. It is also suitable to use :. Butyl acrylate and ethyl acrylate are particularly preferred among the acrylates because of their price, availability, and well-known properties. Methyl methacrylate is particularly preferred among the methacrylates because of its price, availability, and well-known properties.

Halogenated alkenes useful in the present invention include, for example, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, and various polychloro, polyfluoro-, and polybromoalkeas.

Acyclic aliphatic conjugated dienes usefully used in the present invention typically include these compounds having 4 to 9 carbon atoms, such as 1,3-butadiene:2-methyl-1,3-butadiene:2 , 3-dimethyl-1,3-butadiene: and 2-neoethylene-1,3-butadiene. Other hydrocarbon homologs of 1,3-butadiene such as 2-ref clo, 3-butadiene and 2-cyano-1,3-butadiene; substituted linear conjugated interdienes/: linear and side chain conjugated hexadiene: 4
Other straight-chain and side-chain conjugated dienes with up to 9 carbon atoms: and comonomer mixtures thereof are also suitable. 1,3-butadiene hydrocarbon monomers, such as those described above, are preferred because they provide interpolymers with particularly desirable properties. 1,3-Ptadiene/ is the most preferred acyclic aliphatic conjugated diene because of its price, availability, and excellent properties of the interpolymers prepared therefrom.

It is of course also possible, if desired, to use mixtures of two or more of the abovementioned monomers. Most preferred among the above monomers are styrene, mixtures of styrene and butadiene, butyl acrylate, methyl methacrylate, and vinyl acetic acid.

The proportions of monomers used in the oxasily/modified latex can vary widely depending on the particular end use of the composition. Typically, however, the oxazolines are used in relatively small amounts, such as from 0.1 to 20 parts, preferably from 1 to 10 parts by weight of the monomers. Generally, the oxazoline is used primarily to impart the desired self-curing properties to the latex overlay, and other monomers are optionally used to impart other properties to the composition. For example, in the preferred oxazoline styrene//butadiene latex, the oxazoline-modified polymer advantageously exhibits similar physical properties (eg, glass transition temperature and hardness) that are normally associated with styrene/butadiene polymers. However, certain properties of the polymer, particularly adhesion and cross-bonding, are generally increased by the inclusion of oxazoline monomers.

The latices of the present invention further include pendant co-reactive groups.

These groups can react with oxazolines to form covalent bonds (hereinafter referred to as coreactivity).

Co-reactive monomers (ie, monomers containing pendant co-reactive groups) used in the present invention are those containing pendant co-reactive groups that can react with Fi myoxazoline to form a covalent bond. It is understood that reaction of such co-reactive groups with oxazorif groups typically, although not necessarily, renders the oxazoline ring q-term.

Typically, the pendant group of the co-reactive monomer contains a reactive hydrogen atom. Examples of co-reactive groups containing active hydrogen atoms include:
Examples include strong acid groups, weak acid groups, aliphatic alcohol groups, aromatic alcohol groups (ie, phenol groups), amine groups, and amide groups (ie, -CONH, and -COMM- groups). In general, the more reactive, i.e. less stable, of such groups are preferred here, such as acids and aromatic alcohols; Groups with lower molecular weight react more rapidly with the oxazoline ring under milder conditions. Amide groups generally exhibit intermediate reactivity.

Particularly preferred are monomers containing pendant strong at fcFi weak acid groups that include acid anhydride groups. Such monomers include ethylenic monomers containing acid groups or acid anhydride groups such as carboxylic acid groups and sulfonic acid groups. Sulfoether acrylate is an example of a suitable sulfonic acid-containing monomer. Examples of suitable monomers containing carbo/acid groups include itaconic acid, acrylic acid, methacrylic acid, fumaric acid, maleic acid, vinylbenzoic acid, and isopro(nylbenzoic acid). More preferably, acrylic acid , methacrylic acid, fumaric acid, itacone modified, and maleic acid.Maleic anhydride!!! is an example of a suitable monomer containing an acid anhydride group.

Suitable co-reactive monomers containing phenolic groups include ortho- and meta-vinylphenols.

Suitable co-reactive monomers containing aliphatic and doxy groups include, for example, hydroxyethyl acrylate, hydroxypropyl methacrylate and N-hydroxydimethyl-N-methylacrylamide. Styrene derivatives with aliphatic hydroxy groups are also useful.

Suitable monomers for the amide foundation M include acrylamide, methacrylamide, vinylacetamide and α-
Examples include chloroacrylamide. N-methylacrylamide and N-methylmethacrylamide are +C0
This is an example of a monomer containing an NH+ group.

Suitable co-reactive monomers containing amide 7 groups include allylamine, 2-aminoethyl acrylate and 2-aminoethyl methacrylate.

Other monomers that can be suitably used in the coreactive polymer particles are those that can be copolymerized with the coreactive monomer. In general, the monomers previously described as useful in making oxazoline-modified polymers are also useful in making co-reactive polymers. In fact, in preferred embodiments of the invention where the pendant oxazoline groups and the co-reactive groups are present in different parts of the latex particles (i.e. on different polymer chains), the polymer backbone of the co-reactive polymer is It is often desirable to "match" that of the oxazoline-modified polymers; in other words, in this embodiment it is desirable to use the same types of polymers in the same proportions in both the co-reactive polymer and the oxazoline-modified polymer. However, dissimilar polymers can also be used in the preparation of the oxazoline-modified and co-reactive polymers to obtain the specific properties desired.

As in the case of oxazoline-modified polymers, poly! The co-reactive monomer generally contains only a small amount of polymeric units derived from the co-reactive monomer, and the co-reactive monomer is generally used in an amount sufficient to impart the desired self-curing properties to the latex composition and other monomers. These monomers are typically used to impart associated properties to polymers made from such monomers.

In general, when the pendant co-reactive groups are present on a different part of the latex particle from the pendant oxazoline groups, the co-reactive monomer is the monomer used to make the co-reactive polymer (Ll~50). h, preferably α1 to 20% by weight, most preferably 1 to 10% by weight.

When the pendant co-reactive groups are present on different parts of the polymer particles, the co-reactive polymer particles and the oxazoline polymer particles are conveniently prepared by emulsion polymerization techniques. These latexes are conveniently prepared by conventional emulsion polymerization techniques in aqueous acid using conventional additives. That is, the monomer charge desired to be used for the oxazoline-modified latex can be combined with conventional anionic and/or nonionic emulsifiers (e.g., potassium dodecylsulfonate, sodium isooctobenzenesulfonate, sodium laurate, and (nonylphenol ether of polyethylene glycol) α5-5% by weight (based on the filled monomers) in a stirred aqueous medium, and the resulting aqueous dispersion is then polymerized.

Conventional emulsion polymerization catalysts can be used in the latex polymerization, common examples of which include peroxides, persulfates, and azo compounds. Preferred examples are sodium persulfate and potassium persulfate 7.
ate, ammonium persulfate, hydrogen peroxide,
and azodiimpterdiami) T. Catalysts such as redox catalysts activated in the aqueous phase, for example by water-soluble reducing agents, are also suitable. The type and amount of catalyst and the specific polymerization conditions used will typically depend on the other (ie, non-co-reactive and non-oxazoline) monomers used. Polymerization conditions are generally chosen to optimize the polymerization of such polymers. Typically,
The catalyst is in catalytic amount, for example 0 based on the monomer weight.
．． It is used in an amount of 0.01 to 5 weight. Generally, polymerization is -lO
It is carried out at a temperature in the range of -110°C (preferably in the range of 50-90°C). Since the oxazolif groups of the oxazolif monomers can be hydrolyzed or reacted with other monomers at high or low pH, the polymerization is conducted at a pH that minimizes this hydrolysis or reaction. Typically, a pH of 3 to 11 and preferably a ri of 6 to 11 μs are used. More preferably, 1 is preferably 98 in the range of 7 to 10.
Polymerization can be carried out continuously, semi-continuously or batchwise.

Similarly, customary chain transfer agents such as dodecyl mercapta/, bromoform and carbon tetrachloride can also be used in the customary manner in the above polymerizations for controlling the molecular weight of the resulting polymer. Typically, when such chain transfer agents are used, they range from 0.01 to 10 (preferably 0.1 to 5) by weight based on the weight of the monomers used in the polymerization. Use in quantity. Again, the chain transfer agent f used here is somewhat dependent on the particular chain transfer agent used and the particular monomers being polymerized.

Suitable latex polymerization methods are described, for example, in U.S. Pat. No. 4.32.
5゜856, same No. 4,001,163, same No. 3,5
No. 13,121, No. 3,575,913, No. 3,
No. 634,298, No. 2.399,684, No. 2
, 790,735, 2,880°189, and 2,949,386.

When the co-reactive monomer is a monomer containing a pendant weak acid group, such as a carboxyl group, the polymerization is carried out under sufficiently acidic conditions to promote polymerization of the weak acid co-reactive monomer with the other monomers used. is advantageous. Preferably the pH is maintained between 1 and 6, more preferably between 1 and 4. After the polymerization reaction, the pH of the aqueous phase is then adjusted with a base, typically to a pH of 7.5-9, to prevent hydrolysis of the oxazoline rings in the oxazoline-modified latex during the subsequent blending operation. To prevent.

The curable latex compositions of the present invention are advantageously made from an oxasili/modified latex and a co-reactive latex by simply blending each latex in the desired proportions. Generally, the relative ratio of the oxazoline-modified latex to the co-reactive latex is 0.05 to 20 per equivalent of oxazoline y groups in the self-curing latex produced.
The acid group is selected to contain a large amount of acid groups, preferably 0.2 to 5 equivalents, more preferably 0.5 to 2 equivalents. Also,
Better water and solvent resistance and greater tensile strength are generally observed when the latex composition contains approximately comparable amounts of oxazoline-modified polymer particles and co-reactive polymer particles. Preferably, the latex has a fi of 0.1 to 10, more preferably 0.2 to 5, and most preferably 0.40 to 10 particles per co-reactive polymer particle.
Contains 2.5 oxazoline modified polymer particles.

Such blending operations are advantageously carried out at room temperature with mild stirring. The product is an aqueous dispersion containing separated particles of oxazoline modified polymer and separated particles of acid polymer.

Advantageously, the particle size of the oxazoline-modified polymer and the co-reactive polymer and their respective particle size distributions are such that the particles tend to pack well together to form a dense cohesive film. It will be done. These particles may be of relatively uniform size across the pan, or they may be of different sizes such that packing of these particles together during film formation is enhanced. Good too.

The latices of the present invention are advantageously prepared by a two-step emulsion polymerization process when both the pendant co-reactive weak acid groups and the pendant oxazoline groups are present in the same latex particle. In the first stage of polymerization, at least 18! A first monomer mixture comprising this and other copolymerizable monomers is polymerized.

Such first polymerization step is conveniently carried out using substantially conventional emulsion polymerization techniques in an aqueous medium containing conventional additives as described above. Typically, the aqueous phase contains 0.5 to 5% by weight (based on monomer charge) of conventional nonionic or anionic emulsifiers.

Conventional emulsion polymerization catalysts such as those described above can be used in the latex polymerization described above. As mentioned above, when the co-reactive monomer is a monomer containing a pendant weak acid group, such as a carboxyl group, as described below, the polymerization will facilitate copolymerization of the weak acid co-reactive monomer with the other monomers used. It is advantageous to carry out the process under sufficiently acidic conditions. In such a case, the pH is preferably 1 to 6, more preferably 1 to 4.
It is between 0.

Polymerization can be carried out continuously, semi-continuously or batchwise.

Similarly, conventional chain transfer agents, such as those described above, can be used in conventional methods and amounts in the first stage polymerization to adjust the molecular weight of the resulting polymer.

The preferred co-reactive weak acid monomer used in polymerizing the pendant oxazolyph group in the same latex particle as the pendant co-reactive group is a pendant co-reactive weak acid group capable of reacting with the oxazoline group to form a covalent bond. It is a monomer containing. It is understood that the reaction of such a co-reactive weak acid group with an oxazoline group typically, but not necessarily, opens the tζoxazoline ring.

Particularly preferred for the two-step polymerization process according to the invention are ethylenically unsaturated monomers containing pendant weak acid groups (including acid anhydride groups). Illustrative examples of such co-reactive weak acid monomers containing carboxylic acid groups include itaconic acid, acrylic acid, methacrylic acid, fumaric acid, maleic acid, vinylbenzoic acid, and isopro(nylbenzoic acid); most preferred. Examples include acrylic acid, methacrylic acid, fumaric acid, itaconic acid and maleic acid.Maleic anhydride is an example of a suitable monomer containing acid anhydride groups.

In addition to the co-reactive weak acid monomer, the first monomer mixture also includes a wide range of monomers that are copolymerizable with the co-reactive monomer, including at least 1111 other monomers that are not co-reactive monomers and are copolymerizable with the co-reactive monomer. The addition polymerizable monolayer is as described above).

The proportions of monomers used in the first monomer mixture may vary depending on the particular end use of the composition. Typically, however, coreactive weak acid groups are used in relatively small amounts, such as from 0.1 to 20 weights of monomers, preferably from 1 to 10 weights. Generally, the co-reactive weak acid monomer is used as king to impart the desired self-curing properties to the latex composition, and other monomers are used to impart other desired properties to the composition. For example, preferred acids/
In the oxazoline-modified styrene/butadiene latex, the oxazoline-modified polymer is advantageously styrene/butadiene latex.
The co-reactive weak acid monomer, which exhibits properties similar to those commonly associated with butadiene polymers, contributes little to the polymer other than curing properties.

It is noted that weak acid-containing polymers also exhibit increased colloidal stability.

Once one polymerization of the first monomer mixture is completed, the pH of the resulting co-reactive latex may be adjusted such that the oxazoline ring does not significantly react or hydrolyze during subsequent polymerization of a second monomer mixture containing oxazoline monomers. Adjust to a high enough range to make it so. Typically,
It is preferable to adjust the pHff to 3 to 11, preferably 6 to 11, and more preferably 7 to 10. It is advantageous to use any customary water-soluble alkaline substances such as ammonium hydroxide, sodium bicarbonate or sodium hydroxide to raise the pH to the aqueous phase.

A second monomer mixture consisting of an oxazoline monomer and at least one other co-polymerizable monomer that is neither a co-reactive monomer nor an oxazoline and that is capable of reacting with the oxazoline monomer is added to the co-reactive latex. The "other" copolymerizable monomer and oxazoline monomer are p as described above. A second monomer mixture is added to the co-reactive latex under conditions such that these monomers polymerize into or around the co-reactive latex particles. The general conditions used are as described above, with the exception that the pH of the aqueous phase is adjusted to the above range (i.e., to a range sufficient to prevent substantial reaction or hydrolysis of the oxazoline monomer) if necessary during the polymerization reaction. It's Toop.

If necessary or desired, additional amounts of aqueous phase emulsifiers, catalysts, initiators, etc. can be added to the co-reactive latex to accelerate its polymerization prior to or concurrently with the addition of the second monomer mixture.

The second stage of polymerization can be carried out immediately after the production of the co-reactive latex. Alternatively, the co-reactive latex can be made in advance and stored until the second stage polymerization is carried out.

The monomers used in the first monomer mixture are matched with the monomers used in the second monomer mixture, i.e. in the same or substantially similar proportions in both the first and second monomer mixtures. The same or substantially similar monomers can be used, and are often desirable, including styrene, butadiene and oxazoline monomers when used in the first monomer mix. Second
The first and second monomer mixtures can be matched using a monomer mixture of . Of course, matching the skeletons of the first and second monomer mixtures is not essential or always preferred in the practice of this invention. More generally, the selection of the other monomers in the first and second monomer mixtures is such that the resulting latex has the desired physical and chemical properties.

The proportions of monomers used in the second monomer mixture are:
This may vary depending on the particular use and end use of the composition. Typically, however, oxazolines are used in relatively small amounts, such as from 0.1 to 20% by weight of the monomers, preferably from 1 to 10% by weight of the monomers. Generally, oxazoline monomers are used to impart self-curing properties to the latex and other monomers are used to impart other desired properties to the latex.

Advantageously, the second monomer mixture contains 1 mole of co-reactive monomer used in the first monomer mixture, os~20
mol, preferably 0.2 to 5 mol, more preferably O,
Most preferably, the amount of oxazoline monomer used is substantially equal on a molar basis to the amount of Shun monomer used, including OS ~ 2 moles of oxazoline monomer.

After polymerization of the second monomer mixture, the curable latex mixture is changed. Such a composition/li (a)
It consists of a group of discrete polymer particles produced by addition polymerization of monomers comprising a co-reactive monomer and <b) the aforementioned oxazoline monomer and (c) at least one other addition-polymerizable monomer.

If the other monomer in the first monomer mixture is different from the other monomer used in the second monomer mixture,
The latex particles produced will be made from at least two other polymerizable monomers in addition to the oxazoline monomer and co-reactive monomer. Without being bound by theory, it is believed that the polymer particles in the latex made by this method are such that the polymer formed in the second polymer mixture carouses or wraps the polymer formed from the first monomer mixture. It is believed to be a structured latex that is interpenetrated. However, it is recognized that during the polymerization of this second monomer mixture some amount of graft or block copolymer may be formed. The precise polymeric structure of the polymer particles is not considered important to the present invention; an essential feature of the polymer particles is that such particles contain both pendant co-reactive groups and pendant oxazoline groups. be.

Advantageously, the polymer particles have a particle size distribution such that during film formation, the particles are packed relatively closely together to form a cohesive film.

The curable latex compositions of the present invention can be used in a variety of applications including paper coating compositions, adhesives, binders, fibrous nonwoven compositions, and the like.

The latex of the present invention can be used as a film or binder for adhesives by layering the latex to the desired substrate, then dewatering the latex and curing the dehydrated polymer. The dehydration step can be carried out by simply evaporating the aqueous phase under room temperature conditions. Alternatively, increase the temperature (i.e. 50-165
Dehydration can also be carried out using >°C. Curing of the polymer can likewise be carried out at constant temperature. Such room temperature curing can range from a few hours to a few hours depending on factors such as the particular polymer used, the amount of oxazoline and co-reactive groups in the polymer, the thickness of the film adhesive or binder layer, and the amount of cross-linking desired. It takes place over a period of several days. Curing can also be carried out by heating the polymer for a short period of time, preferably to 105-165°C, more preferably 135-150°C. The drying and curing points described above do not need to be separate steps and can be performed simultaneously if desired.

The following Example 1 is intended to illustrate aspects of the invention where the co-reactive groups and oxazolif groups are present in different parts of the latex particles. All parts and parts are by weight unless otherwise specified. 'A 1 gallon jacketed reactor equipped with an FMI experimental pump to deliver the monomer and aqueous feeds was charged with 59011 water, 7 g IIs active (anthanasodium diethylenetriamine-e/taacetate aqueous solution and 24411 A 29-inch solid seed latex was added. The seed latex contained polystyrene particles having a volume average particle size of approximately 0.05 oztspm<zrsA>.

The reactor was purged and heated to 90°C. then over 3 hours 455 JF of butyl acrylate,
A monomer stream containing 211I styrene and 281/acrylic acid was added. 2451 for 4 hours starting simultaneously with the scouring of the monomer stream.
deionized water, 15.56,? 45 active agent aqueous solution, 14. An aqueous solution of IJium hydroxide and 4.9 g of sodium persulfate were added. After addition of the aqueous stream of monomer, the reaction mixture was heated at 90° C. for a further 1 hour and then cooled.

The product was a 44.8 part solid latex of butyl acrylate/styrene/acrylic acid polymer in a weight ratio of 65/31/4.

B. Oxazoline Modified Latex In a 0.0038 rn" (1 gallon) jacketed reactor, 146 parts deionized water, 0.01 parts 0.1 parts sodium diethylene triamine pe/taacetate in water, 5.0 parts Hi-Pal Alphata™ 214 surfactant (commercially available from Hercules Inc.) and 0.5 parts of sodium persulfate were added. The reactor was stirred and purged with nitrogen. The stirred reactor was then stirred and purged with nitrogen. , 25 parts of styrene, 5 parts of 2-
A mixture consisting of isopo4-2-oxazoline (IF□) and 0.5 part of dodecyl mercaptan was added. Then 70 parts of butadiene were added and the mixture was allowed to polymerize for 8 hours at 1:60° C. Then the reactor was opened and 0.5 parts of sodium dimethyl ditheocarbamate were added. This latex was then steam distilled to remove unreacted monomers. The resulting latex contained 33.5% solids and had polymer particles consisting of a butadiene/styrene/IPO terpolymer in a 70/25/50 Mtt ratio. This oxazoline modified latex is referred to as Latex 41 in Table 4 below.

Oxazoline-modified latex 42.3 was prepared using the general method used to prepare latex/W&1, except that the amounts of butadiene//styrene/IPOO and dodecyl mercaptan were varied as shown in Table 1 below. 4 and comparative latex rots C-1, C-2 and C-3 were produced.

No sodium dimethyl dithiocarbamate was added to the latex containing 50 parts of butadiene. These latexes (with the exception of the comparative latexes, of course) are components that are blended to produce latexes according to the invention, and are not themselves compositions of the invention.

Table I 702550.533.5 G-1703000,536,0 2702551,041,7 C-2703001,039,3 3504550,540,9 45040100,537,2 G-3505000,538,4 11-Dodecylmercaptan, etc. A self-curing latex composition was prepared by stirring together the weight (solids basis) of IPOK latex/% 1 and the carboxylated latex at room temperature.

The IPO modified latex and carboxylated latex were compatible at all ratios. The resulting blend is referred to as latex composition/f61 in Table 1 below. Similarly, IPO modified latex 42.3 and 4
and latex composition layer 2.3 by mixing comparative latexes 46C-1, C-2, and C-3 on an equal weight solids basis with the carboxylated latex described above.
and 4 and comparative latex compositions AC-1, C-
2 and C-3 were produced. Sample layer 4 was carboxylated latex alone. Latex composition/161~
4 and comparative latex compositions, 0.511r on Teflon-coated steel plates.
M (20 mil) courtesy film was drawn down and the film was dried at room temperature until clear. The transparent film was then peeled off from the steel plate and further dried for about 24 hours at room temperature. Some of the resulting films were then cured at 80°C, 120°C or 150°C for 5 minutes. The resulting film was then cut into x3R (0.5 inch) wide strips and tested for elongation at break and tensile strength on an Instokun tensile tester. In addition, a sample of the same type was immersed in a 0.5% surfactant aqueous solution for 5 minutes, and the wet film was tested for elongation at break and tensile strength using an in-stack tensile test. These results are summarized in the first section below.
Shown in the table. The elongation value is expressed in wa, and the tensile strength is expressed in megapascals (CMPa).

Band This is not an embodiment of the present invention.

NJ), not measured.

(υ　Cure for 24 hours at room temperature.

(2) Elongation of dry (non-wet) films tested using an Instron testing machine.

(3) Excellent elongation of a film immersed in a 0.5% surfactant aqueous solution for 5 minutes before testing. The test was conducted on an Instron testing machine.

(4) The tensile strength of the dry (non-wet) film tested using an Instron testing machine
) Displayed in units.

(5) Tensile strength (unit: MPα) of a film immersed in a 0.5% surfactant aqueous solution for 5 minutes before the test. The test was conducted on an Instron test machine.

(b) Film cured at 80° C. for 5 minutes before testing.

(7) Film cured at 120°C for 5 minutes before testing.

(8) Film cured at 150°C for 5 minutes before testing.

As can be seen from Table 1, the latex compositions of the present invention generally formed films with higher tensile strength and slightly lower elongation than the comparative latex compositions. The data presented in Table 1 clearly illustrate the improved water resistance exhibited by the latex compositions of the present invention. Films made from the comparative latex compositions exhibited a tensile strength reduction of about 30-70% when wet. In contrast, the latex compositions of the present invention typically exhibit only a tensile strength reduction of about 10 to 2 liters. It is clear that the films made from the comparative latex compositions are also quite sensitive to water.Films made from the latex compositions of the present invention also show a higher sensitivity to water than dry samples. Both exhibit an excellent combination of good elongation and high tensile strength.

In order to measure the degree of cross-linking and solvent resistance, the swelling index and gel of the films cured at room temperature, 100'C1120°C and 150°C were determined as follows.

Multiple film samples were each made from latex compositions/f61 and C-1 using a 0.51 u (0.020 inch) casting rod. Each film was dried until clear and peeled off as a continuous film. One film was tested without curing and the other films were tested after curing for 5 minutes at 100°C, 120°C and 150°C, respectively. The test film was placed in a centrifuge tube.

This (Df tube 301i) was filled with toluene. The tube was sealed and shaken vigorously for 90 minutes.
Centrifuged for 1 hour. The toluene was then removed and the remaining wet gel was weighed. The gel was then dried in an open vacuum to constant weight. Glue and swelling index are calculated from the following formulas, respectively.

The results obtained are shown in the following table.

Room temperature curing 13.86 23.310
0C hardening? , 58 22.62120
℃ hardening 8.23 27.41150℃
Curing 7.02 23.88 Gel - Room temperature curing 81.3 42.03Z
oo℃ hardening 81.65 49.8312
0℃ curing 80.87 46.38150
Cure: 82.99 49.66 band This is not an example of the present invention.

As can be seen from Table 1, the films produced from the latex of the present invention exhibited greatly increased solvent resistance and a greater proportion of insoluble materials than the comparative samples.
Films made from i62.3 and 4 were similarly tested and also showed improved solvent resistance and a greater proportion of insoluble material compared to the control K.

Examples 2-5 below provide a detailed illustration of the invention when the co-reactive group and the oxazoline group are present in the same latex particle.

OJ with laboratory pump delivering monomer and aqueous feed
)038 m' (1 gallon) jacketed reactor, 5
93 g of deionized water, 1% active of 7I
1.9I of 32I solid seed latex (approximately 0.0263
(containing polystyrene particles with a volume average particle size of 100 μm) was added.

The reactor was purged with nitrogen and heated to 90°C. then over 3 hours, 45577 butyl acrylate,
2171 styrene, 28Ii acrylic acid, and 3
．． 81 of 55 active divinylbenzene was added. Starting simultaneously with the start of monomer flow, 245p deionized water, Is, 561 45s active surfactant aqueous solution;
14! ! 10% aqueous sodium hydroxide solution and 4.9
! ! of sodium persulfate was added over 4 hours.

After addition of monomer and aqueous liquid stream, the reaction mixture was heated at 90° C. for an additional hour and then cooled. The product is 6
5/31/410.3% by weight ratio of butyl acrylate/
It was a 45% solids latex of styrene/acrylic acid/divinylbenzene polymer.

1244.0 of the co-reactive latex produced! 0.003 part with 100% water and enough ammonium hydroxide to raise the pH from 3.9 to 8.7.
8 m" (1 gallon) stainless steel reactor, the reactor was then purged with nitrogen, and the 1411 2-
A monomer mixture consisting of isopropenyl-2-oxazoline, 911 butyl acrylate and 35I styrene was added. 1711 parts of dehydrated ionized water and 0.7 II parts of sodium persulfate were also added. The resulting mixture was then heated to 60°C
The mixture was polymerized for 8 hours and then cooled. The latex produced is
It contained polymer particles with both pendant acid groups and pendant oxazoline groups as determined by infrared spectroscopy.

The resulting latex was thickened with a small amount of sodium polyacrylate and a 0.51 m (20 mil) thick film of this latex was coated with Teflon using a 0.510 (20 mil) thick film rod. Cast on coated steel plate. The film was dried at room temperature until clear - then peeled from the steel plate and dried for an additional approximately 24 hours at room temperature.

This air-dried film was then cured for 5 minutes in an oven set at various cure temperatures listed in Table 1 above. The cured film was then tested in 130 (0.5 inch) strips in a cut-reinstro/testing machine to determine elongation and tensile strength at break. A cured film of the same type was immersed in an excess amount of an aqueous solution containing 0.5% Agroso 107' surfactant for 5 minutes and then measured for elongation and tensile strength at break. For comparison, a sample of carboxylated latex without suspended oxazoline groups was formed into a film and tested as described above. The results obtained from the test of this comparative example are shown in Table 1 as Sample/16cm1.The results obtained for the 9 film produced from the latex of the present invention are shown in Table 2 as Sample/161. The tensile strength fL is given in MPa.

Table ■ Comparative Example Wet Tensile Strength” 6.27 2.
64 Elongation when drying') 351 41
3 Wet elongation 5 inches 285 435 Dry tensile strength 9,55 6.65
Tensile strength when wet 7.75 3.2
5 Elongation when dry 304 395 Elongation when wet 275 443 Cured at 120°C (7) Tensile strength when dry 9,38 5.8
7 Tensile strength when wet 8.96 2.
61 Elongation when dry 268 399 Elongation when wet 283 401 Tensile strength when dry 10.07 5.94 Tensile strength when wet 11,36 3.87 Elongation when dry 236 403 Tensile strength when wet Elongation: 260 504 band This is not an actual example of the present invention.

a) Film cured at room temperature for 24 hours.

(Tensile strength expressed in units of CMPα of the film cured at the stated temperature measured on the dry film using a 2 Instron testing machine).

(3) Tensile strength (expressed in MPc) of the film cured at the indicated temperature measured on the film immersed for 5 minutes in a 0.5% surface active agent aqueous solution before Test 1, test ta
The tests were carried out using an Instron tensile tester.

(4) Elongation of film cured at stated temperature measured on dry film using an Instron testing machine.

(5) Elongation of the film cured at the stated temperature measured on the film immersed in the surfactant aqueous solution immediately before the test.

Testing was performed on an Instron tensile testing machine.

(b) Film cured at 100°C for 5 minutes.

(7) Film cured at 120°C for 5 minutes.

(8) Film cured at 150°C for 5 minutes.

As can be seen from Table 1, the latex of the present invention produced films with higher tensile strength than films made from the control latex. Even more strongly, the films of the present invention do not suffer significant damage when the film is immersed in surfactant-containing water. In fact, at high curing temperatures, wetting the film increases its tensile strength. In contrast, the control sample significantly loses tensile strength upon immersion in the surfactant solution.

, m@J 3 In this example, a co-reactive latex (51% solids) comprising a styrene/butadiene/7-malic acid terpolymer (57,6/4 CL5/L9 weight ratio) was used as the starting material.

158,411 portions of this latex were added to a 0-0038 Corner 1 (1 Ga cIy) stainless steel reactor. Sufficient ammonium 28 thihydroxide water bath solution was added to the latex to raise the pH to about &5. Then 19
8 g of deionized water, 2I of 1% active sodium dietre/triamine (interacetate solution), 1 g of sodium persulfate, 20# of 2-isoproynyl-2-oxazolyl, 99 fl of styrene, and 4 g of carbon tetrachloride. The reactor was then purged with nitrogen to 81.9'
of butadiene was added. The reaction mixture was then stirred at 60°C.
The latex was heated for 80 minutes, and then the latex was steam distilled to remove unreacted slag. The resulting latex was confirmed by infrared spectroscopy to reveal the presence of pendant reactive groups and pendant oxacyl groups.
It contained particles with both groups. A film was made from the resulting latex and cured as described in Example 2 above. The tensile properties of the resulting film were tested as described in Example 2. The results are shown in Table V below.

For comparison, a portion of the co-reactive latex that was not modified with the oxazoline polymer was formed into a film, cured and tested as described in Example 2. The results are shown as sample layer 2 in Table V below.

This is not an embodiment of the present invention.

Note: (1) to (8) are listed in Table ■.

It can be seen from this table that the dry tensile strength of the carboxylated IPO modified latex is substantially equal to that of the dry carboxylated latex. However, when evaluating the wet tensile strength, the films made from the latex of the present invention (comparative samples) are clearly superior.

In this example, a 48.6% solids latex of a 58/38/4 ratio styrene/butadiene/acrylic terpolymer was used as the co-reactive starting material.

A 1646g portion of this latex is 0.0038m"
(1 gallon) stainless steel reactor. A sufficient amount of aqueous ammonium 28 thihydroxide was added to the latex to raise the pH to about 8.6. Then 198 g of deionized water, 1 I of sodium persulfate, 2.0 g of active sodium diethylenetetramine (in taacetate solution), 2-isopropenyl-2-oxazoline of 2011, 96 g of styrene, and 6110 carbon tetrachloride were added to this mixture. Add 9 to the reactor.Then the reactor is purged with nitrogen and 84
g of butadiene was added.

The resulting mixture was then polymerized at 60° C. for 7 hours. The resulting latex contained particles with both pendant acid groups and pendant oxazolyph groups. A film was prepared from the resulting latex by the method described in Example 2 and tested for tensile properties. The results are shown in Table 1. For comparison, a film was prepared from a carboxylated latex containing no oxazolif groups.

These films were tested for tensile properties "4c" and the results are shown in Table 2 below as sample J46C-3.

Table ■ Tensile strength when wet (3) 6.64
9.74 Elongation when drying 411 3
70 Wet elongation 315 276
Cured at 100°C (b) Tensile strength when dry 12,54 12.
75 Tensile strength when wet 10,41 9
．． 74 Elongation when drying 406 39
5 Elongation when wet 347 2761
Cured at 20°C (η Tensile strength when drying 10A1 12A
7 Tensile strength when wet 11.02 12
j5 Elongation when drying 403 378
Elongation when wet 348 34215
Cured at 0°C (8) Tensile strength when dry 13.44 110
2 Tensile strength when wet 13.85 11
45 Elongation when drying 355 377
Elongation when wet 324 331 band
In embodiments of the present invention, there is no power.

Note: (1) to (8) are listed in Table ■.

Again, the excellent tensile properties of the wet and dry films of the invention were observed.

Example 5 Eleven glass reactors immersed in a temperature-controlled water bath were charged with 359
g of deionized water, 3I! 4. a solution of 1 active intansium diethylene triamine acetate; and 4.
5g of 32% solids seed latex (containing polystere/polymer particles) was added. The reactor was purged ff1 times and heated to 83°C.

Then over 1 hour 90.9 g of butyl acrylate, 53.75 g of methyl methacrylate and 5.
A first monomer stream containing 0 g of acrylic acid was added. After the first monomer addition, the reactor was held at about 83° C. for 15 minutes. A solution of 3I 28 amthonium thihydroxide was added to raise the pH from 3.5 to 8.3 and then the second monomer flow was started.

A second monomer stream was added over 1 hour. Second
The monomer flow is 901 butyl acrylate), 53
．． 751 of methyl methacrylate, and 7.51 of 2-isopropenyl-2-oxazoline. 2I starting at the start of the addition of the first monomer
Over 4 hours, 90g deionized water, 1.5g sodium persulfite, 0.3y hh OH, and 3.
An aqueous stream containing a 45% active surfactant solution of 3Ii was also added. After addition of the first monomer stream and the aqueous stream,
The reactor was held at 83° C. for an additional hour and then cooled.

The latex was formed into a film as in Example 2.

This film was cured by heating at 125° C. for 5 minutes, and then tested for tensile strength and elongation as in Example 2.

The results are shown in Table 1 below.

For comparison, films were manufactured in the same manner from the following various latexes.

Sample/%C-4A Butyl acrylate/Methyl methacrylate (b0/40) Sample 116cm4B Butyl acrylate/Methyl methacrylate/Acrylic acid (b07 38,33/1.67) Sample 716cm4G Butyl acrylate/Methyl methacrylate/2-iso Propenyl-2-oxazoline (b0/37.5/2.5) Sample A6C-4D So of C-4B and C-4C:
s.

All O blend films were tested for tensile strength and elongation as described above. The results are shown in the following table.

Australia This is not an embodiment of the present invention.

(υ　Same as note (2) in Table ■.

(2) Same as note (4) in Table ■.

(3) Notes to Table ■ (same as 3).

(4) Same as note (5) in Table ■.

As can be seen from the data in Table 1, films made from the latex of the present invention exhibit the highest tensile strength in both wet and dry tests.

Patent Applicant: The Dow Chemical Company,
−\.

Claims (1)

[Scope of Claims] 1. A curable latex composition consisting of a group of separated polymer particles, the polymer portion of which has (a) co-reactivity containing a pendant group capable of reacting with an oxazoline group to form a covalent bond; monomer and (b) general formula▲numeric formula, chemical formula, table, etc.▼ [However, R^1 is an acyclic organic group with addition polymerizable unsaturation; each R^2 is independently hydrogen, halogen, an inert substituted organic group; n is 1 or 2] and (c) at least one other addition-polymerizable monomer that does not contain a co-reactive group or an oxazoline group. 1. A curable latex composition comprising a polymerized latex composition, with the oxazoline group and co-reactive group being suspended. 2. The composition of claim 1, wherein both (a) the pendant co-reactive group and (b) the pendant oxazoline group are present in the same latex particle in at least a portion of the group of latex particles. thing. 3. Claims in which (a) the pendant co-reactive group is present on one portion of the latex particles, and (b) the pendant oxazoline group is present on a second separate portion of the latex particles. The composition according to item 1. 4. The composition according to claim 1, wherein the co-reactive group is a weak acid, aliphatic alcohol, aromatic alcohol, amine or amide group. 5. The composition according to claim 1, wherein the co-reactive monomer is an α,β-ethylenically unsaturated carboxylic acid or an acid anhydride. 6. The composition according to claim 1, wherein the oxazoline is 2-isopropenyl-2-oxazoline. 7. A method for producing a latex consisting of a separate group of particles containing both pendant co-reactive weak acid groups and pendant oxazoline groups, comprising the following steps: (a) addition-polymerizable monomer containing pendant weak acid groups; and at least one other addition-polymerizable monomer copolymerizable with the weak acid monomer at a pH in the range of 1 to 6 to form particles of a polymer containing suspended weak acid groups. (b) adjusting the pH of the resulting latex to a value at which the addition-polymerizable oxazoline does not substantially react or hydrolyze under conditions suitable for its polymerization; and (c) adding (1) to the latex. General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, R^1 is an acyclic organic group with addition polymerizable unsaturation; each R^2 is independently hydrogen, halogen, or an inert substituted organic group. n is 1 or 2] and (2) at least one other monomer that does not contain a pendant co-reactive weak acid group or a pendant oxazoline group. and (d) polymerizing these monomer mixtures under conditions such that a second monomer mixture polymerizes within or around the pendant co-reactive weak acid group-containing polymer particles. A method characterized by: 8. The first monomer mixture is α,β-ethylenically unsaturated carboxylic acid and monovinyl aromatic monomer or α,β-
an ethylenically unsaturated carboxylic acid alkyl ester or an aliphatic conjugated diene; the second monomer mixture is an addition polymerizable oxazoline and a monovinyl aromatic monomer or an α,β-ethylenically unsaturated carboxylic acid alkyl ester or an aliphatic conjugated diene; Claim 7 consisting of
The method described in section. 9. The method according to claim 7, wherein the oxazoline is 2-isopropenyl-2-oxazoline. 10. The method according to claim 7, wherein the pH is adjusted to 7 to 11. 11. The method of claim 7, wherein the second monomer mixture contains from 0.5 to 2 moles of oxazoline per mole of co-reactive monomer used in the first monomer mixture. 12, the co-reactive monomer is acrylic acid, methacrylic acid, itaconic acid or fumaric acid, and the oxazoline is 2
-isopropenyl-2-oxazoline.The method according to claim 8.