JPS609048B2 - Method for manufacturing polymer latex - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a latex of a polymer by adding an emulsifier and water to an organic solvent solution of a polymer to emulsify it, and removing the organic solvent from the resulting emulsion.

Conventionally, polymer latexes other than naturally obtained natural rubber latexes have been produced exclusively by emulsion polymerization and put into practical use.

On the other hand, in recent years, advances in polymerization techniques such as solution polymerization have made it possible to obtain polymers having unique structures and physical properties, and polymer latexes having such structures and physical properties have been attracting attention. The general method for obtaining these polymer latexes is to add an emulsifier and water to a polymer solution or solid polymer dissolved in a suitable organic solvent to emulsify it. This method produces latex by removing the solvent from the emulsion.

If the latex thus obtained has a low polymer content, it may be concentrated by operations such as creaming, centrifugation or water evaporation. However, when the latex thus obtained is to be transported or blended for final use, it has the disadvantage of significantly inferior mechanical stability compared to latex obtained by emulsion polymerization.

That is, when large mechanical shear forces are applied to the relatively mechanically unstable latex thus obtained, it can be used, for example, as paints and adhesives, when mixing pigment pastes and painting, and for paper processing. During pigment blending and coating, as well as during mumble drawing in the field of textile processing, aggregates may be formed partially or, in severe cases, entirely due to contact and fusion between latex particles. , latex may lose its original function.
This tendency is particularly remarkable when mechanical shearing force is applied at high temperatures. The purpose of the present invention is to add an emulsifier and water to an organic solvent solution of a polymer, and remove the organic solvent from the resulting emulsion to produce a polymer latex. Together with an activator or anionic surfactant and a nonionic surfactant, in the general formula (ta), R is an aryl group, an aralkyl group, or an alkyl group having 8 to 18 carbon atoms, LR2 is hydrogen or an alkyl group having 8 or less carbon atoms. represents a group, n and m are 1 and 3
is an integer of , m+n is 5 or less, and n or m
When R is 2 or more, R or R2 may be different from each other.

The purpose of this invention is to obtain a latex with excellent mechanical stability by using a compound obtained by adding ethylene oxide to an aldehyde condensate of phenols represented by ().

The polymer used in the present invention is soluble in organic solvents, substantially insoluble in water, and contains one or more naturally occurring or polymerizable monomers. Polymers obtained by polymerizing a mixture of
Further, these may be chlorinated or chlorosulfonated, or a blend of two or more of these may be used. Examples of the polymer include the following.
Natural rubber, butadiene polymer, isoprene polymer, cyclobentadiene polymer, styrene-butadiene copolymer, styrene-isoprene copolymer, ethylene-propylene copolymer, ethylene-propylene-genes copolymer (EPDM) ), isoprene-isobutylene copolymer, butadiene-acrylonitrile copolymer, ethylene polymer, ethylene-vinyl acetate copolymer, propylene polymer,
Examples include butadiene-propylene copolymers, butadiene-ethylene copolymers, butene polymers, and the like.

Among these, the polymers particularly preferably used in the present invention are:
Styrene-butadiene random or block copolymers, styrene-isoprene block copolymers, isoprene polymers, ethylene-propylene-genes copolymers (E
PDM) etc. These polymers may contain oil extenders, oil lagoon plasticizers, and softeners.

As oil malleability and plasticity softeners, dioctyl phthalate,
Synthetic ester plastics such as dibutyl phthalate, diisodecyl phthalate, diisodecyl adipate, dioctyl sebacate, acetyl citrate, butyl stearate,
Paraffinic, naphthenic, and aromatic petroleum hydrocarbons having a boiling point of 200 oo or higher, mixtures thereof, natural or synthetic resins such as terben resin, phenol resin, rosin-brewed gin, coumaron-brewed gin, and modified products or mixtures thereof. Examples include natural oils such as terben oil and tall oil.The type of organic solvent used in the present invention is not particularly limited as long as it is substantially insoluble in water.

A commonly used and preferred organic solvent has a boiling point of 1800
0 or less aliphatic, alicyclic, aromatic hydrocarbons, or halides thereof, and a mixture of these may be used. However, when using a halide, it is preferable to mix it with another type of solvent. Further, the organic solvent solution of the polymer used in the present invention may be a polymer solution obtained by solution polymerization, or may be a solid polymer dissolved in the above-mentioned organic solvent.

The concentration of the polymer solution is not particularly limited, but
It is usually used in a range of 5% to 5% by weight, preferably 1% to 4% by weight. If it is less than 5% by weight, the productivity is poor, and if it is more than 5% by weight, the viscosity of the solution increases significantly, and the preparation of the solution itself is difficult.
Furthermore, the emulsification operation is also difficult and undesirable.

A compound in which ethylene oxide is added to an aldehyde condensate of phenols, which is represented by the general formula '1} and is used as a part of the emulsifier or dispersion stabilizer in the present invention, can be prepared as follows.

That is, a phenol represented by the general formula {11 and an aldihyde such as formaldehyde are reacted by heating in an ethanol solution in the presence of hydrochloric acid, the resulting product is dissolved in toluene, and ethylene oxide is reacted in the presence of sodium hydroxide. Obtained by blowing. Phenols represented by the general formula tl} include Z such as octylphenol, nonylphenol, phenylphenol, benzylphenol, tolylphenol, Q- or 8-phenylethylphenol, phenylpropylphenol, biphenylyl. Examples include phenol, naphthylphenol, phenylcresol, benzylcresol, Q- or 6-phenylethylcresol, phenylxylenol, polyphenylalkylphenol, and the like.

The degree of polymerization of these aldehyde condensates of phenols is preferably between 2 and 9, and increasing the degree of polymerization more than that is meaningless in terms of effectiveness, and in that case, the solubility will be poor and handling will be difficult.

The amount of ethylene oxide added is shown by the HLB value (HLB=B/5, E is formula '1) that indicates surface activity so that the ethylene oxide content% relative to the whole is 6.7 and 16.7. Preferably, the amount is between 50 and 50 parts by weight per 10 parts by weight of the aldehyde condensate of phenols. This ethylene oxide addition portion may partially contain propylene oxide as a random or block copolymer. In the present invention, the amount of the compound obtained by adding ethylene oxide to the aldehyde condensate of phenols represented by the general formula (1) used as a part of the emulsifier or dispersion stabilizer is 0 to 100 parts by weight of the polymer. .2 to 15
parts by weight, preferably 0.5 to 5 parts by weight, and 0.
．． If the amount is less than 2 parts by weight, the effect will not be sufficiently exhibited, and if it exceeds 15 parts by weight, the viscosity of the latex will increase more than necessary, and the physical properties in the final use, such as the tensile properties and adhesive properties of the film, will decrease. So I don't like it.

Further, as for its usage, it may be added to the polymer solution or water as part of an emulsifier before emulsification, or it may be added as a dispersion stabilizer after removing the solvent. Furthermore, the patent application 1976-76532 (Tokukan Sho 50-
No. 2684y), Japanese Patent Application No. 7653 (Sho 48-7653)
It may also be added as a dispersion stabilizer to a latex containing some solvent or plasticizer, as shown in No. 0-26848). The compounds of the present invention exhibit a strong stabilizing effect by any method. Note that the ethylene oxide adduct or other surfactant of the present invention used as an emulsifier serves as a dispersion stabilizer in the latex after the solvent is removed. The ethylene oxide adduct of the present invention is
Used with anionic surfactants or anionic surfactants and nonionic surfactants. The ethylene oxide adduct of the present invention is a type of nonionic surfactant. Generally, nonionic surfactants have weak emulsifying power and latex dispersion stability when used alone, but when used in combination with anionic surfactants, This makes it possible to obtain latex with excellent mechanical stability. These surfactants are not limited to specific ones, and various types of known surfactants can be used. For example, rosin acid salts (including salts of disproportionated rosin acid and hydrogenated rosin acid), higher fatty acid salts, higher alcohol sulfate ester hydrochloric acid, higher alkyl ether sulfate ester salts, alkylbenzene sulfonate salts,
Anionic surfactants such as mono- or dialkylnastalene sulfonates, dialkyl sulfosuccinates, various phosphate ester salts, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenol ethers, polyoxy Examples include nonionic surfactants such as polyoxyethylene type surfactants such as ethylene alkyl esters and polyoxyethylene alkyl amines, and block types of polyoxyethylene and polyoxypropylene.
It is particularly preferable to use a combination of an anionic surfactant and a nonionic surfactant as an emulsifier because a good emulsion can be obtained.

Examples of combinations include: {a} Anionic surfactants such as higher fatty acid salts, rosin acid salts (including disproportionated rosin acids and hydrogenated rosin acids), dialkyl sulfonates, dialkyl sulfosuccinates, {b}
A nonionic surfactant represented by the general formula R,1(0-R2-)nOH (wherein R is an alkyl group having 8 to 18 carbon atoms, or an alkylphenyl group having an alkyl group having 8 to 18 carbon atoms) , or a group having two or more aromatic nuclei, and R2 represents an alkylene group having 2 to 5 carbon atoms.

n is an integer from 8 to 50). The amount of these emulsifiers used is not particularly limited, but is usually 0.5 to 15 parts by weight based on 10 parts by weight of the polymer.

There is no need to limit the type of emulsifying machine for emulsifying the polymer solution, emulsifier, and water, and any known emulsifying machine may be used as long as it has a sufficiently strong emulsifying ability.

Examples of emulsifiers that can be used include homomixers, homogenizers, disper mills, and colloid mills, and two types of emulsifiers can be used in combination if necessary. The next step in the present invention is to remove the solvent from the emulsion obtained, which can be preferably carried out by heating through a jacket in an evaporator or by directly blowing steam, which is a common method for removing solvent. , Methods other than the above-mentioned methods, such as Tokubuta No. 49-94002 (1989-94002), which precedes the present application.
There is also a method using a centrifugal thin film evaporator as shown in Japanese Patent Application Laid-Open No. 51-23534), and any method may be used. The latex thus obtained usually has a solid content concentration of about 5 to 65% by weight, but if the solid content concentration is low, it may be concentrated if necessary.

Methods for obtaining concentrated latex include creaming, centrifugation, and water evaporation, but the far-D separation method is particularly preferred because of its high reproducibility.
By implementing the present invention, no matter which concentration method is used, aggregation and precipitation of latex particles are extremely small, and concentration can be easily achieved. The concentrated latex obtained by the present invention can be used for imprinted products, foam rubber, rubber thread,
It can be used in a wide range of applications, including processed paper, carpet sizing agents, fiber processing agents, surface cornering agents, adhesives, paints, binders, latex-added asphalt, and cement compounding agents.

The present invention will be explained in more detail in the following examples, but the present invention is not limited thereto.

Example 1 Contains 10 parts by weight of a thermoplastic elastomer (Sorprene T414) produced by solution polymerizing styrene and putadiene.
To a 2% by weight toluene solution, 2.5 parts by weight each of unbounded rosin acid and 2.5 parts by weight of polyoxyethylene nonylphenyl ether with an oxyethylene polymerization degree of 15; 2)1
Add 2.5 parts by weight of a compound prepared by adding 10 parts by weight of ethylene oxide to 0 parts by weight, mix and dissolve, and dissolve this solution and sodium hydroxide in an equimolar amount as the disproportionated rosin acid. The resulting aqueous solution was mixed at a polymerization ratio of 1:1 and emulsified using a disper mill.

The produced emulsion containing toluene was immediately sent to a toluene removal tank having a heating jacket, and toluene was evaporated and removed by heating. At this time, a part of the water evaporated together with toluene to obtain a dilute latex with a solid content concentration of 24.5% by weight. This was sent to a cylindrical centrifuge and operated at approximately 12,000 rotations (approximately 600 rotations) to obtain a concentrated latex (solid content concentration of 57.2% by weight). The amount of agglomerated and precipitated copolymer in the concentration step was 0.2% by weight or less.The mechanical stability of the obtained concentrated latex at room temperature (JIS K
-6381 method) is 1800 seconds or more, and mechanical stability at high temperatures (JISK-6381 method 70 seconds or more).
applied at qo) was 60 sand. Comparative Example 1 2.5 parts by weight of disproportionated rosin acid as an emulsifier, poljoxyethylene nonyl phenyl ether with an oxyethylene weight of 15, and 5. A concentrated latex (solid content concentration 54.4
Weight percent was obtained.

The amount of copolymer coagulated and precipitated in the step of evaporating and removing toluene and the step of concentrating by centrifugation was 1. % by weight. The mechanical stability of the obtained concentrated latex was 120 seconds at room temperature and 150 seconds at high temperature (700C). Example 2 Butadiene-0 styrene-butadiene-styrene block copolymer rubber polymerized using a lithium catalyst (molecular weight 70,000, bound styrene content 40% by weight, 3 boxes containing 10 parts by weight) Rosin acid 3
Add and mix 3 parts by weight of polyoxyethylene nonyl phenyl able having a degree of polymerization of oxyethylene of 12 and dissolve the solution, and an aqueous solution in which an equimolar amount of sodium hydroxide as the disproportionated rosin acid is dissolved. were mixed at a weight ratio of 2:1 and emulsified using a disper mill.

By evaporating toluene from the produced emulsion containing toluene, a latex with a solid content concentration of 50.2% by weight was obtained. The amount of agglomerated and precipitated block copolymer in the solvent removal process is 1. % by weight. The latex contains a formaldehyde condensate of norniphenol (average degree of polymerization 2).
．． 5) 1.5 parts by weight of a compound prepared by adding 300 parts by weight of ethylene oxide to 10 parts by weight was added, and the mechanical stability was measured after aging for 3 days. Mechanical stability at room temperature is 180 or higher at room temperature, and 36 at high temperature (7000).
It was actual sand. Example 3 The following compound was added to the latex instead of the ethylene oxide adduct of the formaldehyde condensate of nonylphenol used in Example 2, and the mechanical stability after aging for 3 days was measured.

1.5 parts by weight of a compound obtained by adding 20 parts by weight of ethylene oxide to 10 parts by weight of a formaldehyde condensation* product of octylphenol (average degree of polymerization 5).

(B} 1.5 parts by weight of a compound obtained by adding 300 parts by weight of ethylene oxide to 10 parts by weight of a formaldehyde condensate of Q-phenylethylphenol (average degree of polymerization 2). ) 1.5 parts by weight of a compound obtained by adding 20 parts by weight of ethylene oxide to 10 parts by weight of a formaldehyde condensate of phenol (average degree of polymerization 2).

(2) 1.5 parts by weight of a compound obtained by adding 10 parts by weight of ethylene oxide to 100 parts by weight of a formaldehyde condensate of tri(Q-phenylethyl)phenol (average degree of polymerization 3). Table 1 shows the measured values of the mechanical stability of the latex after aging.

Comparative Example 2 Table 1 shows the mechanical stability of the latex obtained in Example 3 without adding the ethylene oxide adduct of the formaldehyde condensate.

Table 1 Measured values of mechanical stability (Example 3, Comparative Example 2) Example 4 Ethylene-propylene-ethylidene norbornene terpolymer with a Mooney viscosity (M°C) of 65 (Mitsui EPT3070 Mitsui Oil Co., Ltd.) A formaldehyde condensate of di(Q-phenylethyl)phenol (average degree of polymerization of 2
) Add 5 parts by weight of a compound prepared by adding 20 parts by weight of ethylene oxide to 10 parts by weight, mix and dissolve, mix the solution and water at a weight ratio of 1:1, and emulsify with a disper mill. .

The produced emulsion containing hebutane was immediately sent to a hebutanization tank equipped with a heating jacket, and the hebutane was evaporated off by heating. At this time, some of the water evaporated together with hebutane to obtain a dilute latex with a solid content concentration of 11.2% by weight. This is sent to a cylindrical far-zero separator, and approximately 1
Operate at 0000 rotations (approximately 500 rotations) to create a concentrated latex (
Solid content concentration 52. We were able to obtain the nebula amount%. The amount of copolymer coagulation and precipitation in the step of evaporating hebutane and concentrating it by centrifugation is 2. It was mother weight %. The mechanical stability of the obtained concentrated latex is 180 at room temperature.
It was more than 48 inkstone sand at high temperature (70oo). Comparative Example 3 An attempt was made to obtain a latex by performing the same operation as in Example 4 using only 1 part by weight of sodium dioctylsuccisulfonate as an emulsifier, but "most of the copolymer aggregated during the centrifugation operation. It was impossible to manufacture it.

Example 5 Mooney viscosity (M string.

C) polyisoprene rubber with 78 (Califlex IR)
305 Shell Chemical ■) 1% by weight, including 10 parts by weight
5 parts by weight of disproportionated rosin acid and formaldehyde condensate of phenylphenol (average degree of polymerization 2) 1 part by weight in a benzene solution
Compound to which 30 parts by weight of ethylene oxide is added 2. A concentrated latex with a solid content concentration of 60.2% by weight was obtained by adding 2 parts by weight and carrying out the same operation as in Example 1.
The mechanical stability of the latex was 180 mm or more at room temperature and 120 mm at high temperature (7000 mm). Comparative Example 4 Using only 7 parts by weight of disproportionated sodium rosinate as an emulsifier, the same procedure as in Example 5 was carried out except for the following:
A concentrated latex with a solid content concentration of 56.5% by weight was obtained.

The mechanical stability of the latex was 150 sand at room temperature and 600 seconds at elevated temperature (7000). Example
6 Thermoplastic elastic body used in Example 1 (Solprene T414
5 parts by weight of naphthenic oil (viscosity specific gravity constant VGC: 0.870) were added to a 20% by weight toluene solution containing 100 parts by weight, and uniformly dissolved and mixed.

2. Add sodium dibutylnaphthalene sulfonate to the solution.
5 parts by weight, 2.5 parts by weight of polyoxyethylene nonylphenyl ether with an oxyethylene polymerization degree of 15, and di(
2.5 parts by weight of a compound prepared by adding 10 parts by weight of ethylene oxide were added to 10 parts by weight of a formaldehyde condensate of (Q-phenol ethyl)phenol (average degree of polymerization 2), and the mixture was mixed and melted. The other operations were the same as in Example 1, and the solid content concentration was 56. A box weight % concentrated latex was obtained. The mechanical stability of the latex is 180M seconds or more at room temperature,
At high temperature (7000) it was 120 inkstone sand. Comparative example
5 Using only 2.5 parts by weight of sodium dibutylnaphthalene sulfonate and 5 parts by weight of polyoxyethylene nonyl phenyl ether as emulsifiers, the same operation as in Example 6 was carried out, except that a solid content of 58% by weight was obtained. A concentrated latex was obtained.

The mechanical stability of this product was 60 seconds at room temperature and 120 seconds at high temperature (70oo). Example 7 A compound obtained by adding 10 parts by weight of ethylene oxide to 10 parts by weight of a formaldehyde condensate of di(Q-phenyl ethyl)phenol (average degree of polymerization 2) was added to the latex obtained in Comparative Example 5 to form a latex solid. For 10 parts by weight, 5. parts by weight were added and aged for 3 days.

The mechanical stability of the obtained latex was 180 quartz sand or higher at room temperature, and 100 quartz sand at high temperature (7000 ℃). Example 8 The following polymer was used in place of the polymer used in Example 2,
A latex was produced in the same manner as in Example 2, and the solid content concentration and mechanical stability of the obtained latex were measured.

The results obtained are shown in Table 2. 1 Butadiene-styrene block copolymer (manufactured by Kraton 1101 Shell Chemical)
D Isoprene-styrene block copolymer (Kraton 1107 manufactured by Shell Chemical ■) m Butadiene-styrene block copolymer (Krato 1101) and Mooney viscosity (
Polyptadiene rubber (Gen 3
Blend product (manufactured by Asahi Kasei Kogyo Co., Ltd.) (blend ratio 1:1)
Comparative Example 6 Table 2 shows the measurement results of solid content concentration and mechanical stability when the formaldehyde condensate of phenols in Example 8 was not added.

Table 2 Measured values of solid content and mechanical stability of obtained Latinx (Example 8, Comparative Example 6) Examples 1 to 8, Comparative Examples 1 to
As is clear from Table 6, the latex obtained by the present invention exhibited much higher mechanical stability than the latex obtained by the conventional technique shown in the comparative example.

Claims (1)

[Claims] 1. When producing a latex of a polymer by adding an emulsifier and water to an organic solvent solution of a polymer and emulsifying it, and removing the organic solvent from the obtained emulsion, it can be used as an emulsifier or a dispersion stabilizer. , an anionic surfactant or an anionic surfactant and a nonionic surfactant together with a compound obtained by adding ethylene oxide to an aldehyde condensate of phenols represented by the general formula (1), per 100 parts by weight of the polymer. A method for producing a polymer latex with excellent mechanical stability, characterized by using 0.2 to 15 parts by weight. General formula (1) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, R_1 is an aryl group, an aralkyl group, or an alkyl group having 8 to 18 carbon atoms, R_2 is hydrogen or an alkyl group having 8 or less carbon atoms, and n and m is an integer from 1 to 3, m+n is 5 or less, and when n or m is 2 or more, R_1 or R_2 may be different from each other.)