JPS6220515A - Production of polymer aqueous dispersion - Google Patents

Abstract

PURPOSE:To obtain the titled dispersion of each high mechanical stability, filler dispersibility and adhesivity to hydrophobic fiber, by emulsion polymerization between butadiene, unsaturated carboxylic acid and comonomer in the presence of specific compound and naphthalenesulfonic acid salt-formalin condensate. CONSTITUTION:The objective dispersion can be obtained by polymerization between butadiene, ethylenic unsaturated carboxylic acid (e.g., acrylic acid), and another ethylenic unsaturated monomer (e.g., styrene) in the presence of, as essential emulsifying agent, (A) a compound of formula (R is 1-12C alkyl; n is integer 2-20; M is Na, K, or NH4) and (B) naphthalenesulfonic acid salt- formaline condensate. This dispersion has such stability as to give 0.02wt%, based on the solid content, of coagulated product when subjected to the Maron- type stability tester (at 1,000+ or -20rpm).

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a mechanically stable filler with excellent dispersibility, /IJ
This invention relates to a method for producing a novel aqueous polymer dispersion that exhibits particularly excellent adhesion to hydrophobic fibers such as xololene, nylon, and polyester.

[Prior art]

Conventionally, pile fabrics and fabrics for 7-tread carpets, chair upholstery, car seats, artificial lawns, etc. are generally used for the purpose of fixing /4' piles, bonding secondary base fabrics, and imparting dimensional stability and elasticity. Specifically, various additives such as inorganic fillers such as calcium carbonate and aluminum hydroxide, and thickeners are blended as necessary with polymer aqueous dispersions such as SDR latex, natural rubber latex, and synthetic resin emulsions. The composition is backed.

Recently, polyzoropyrene split yarn fabrics have been increasingly used as the primary base fabric (base fabric for inserting piles) of artificial grass in tufted carpets. However, this polypropylene fabric is non-polar and has almost no water absorption, so when it is backed with a conventional composition containing an aqueous polymer dispersion, the peel strength of the secondary base fabric (backing) is insufficient. Not even JJ? The suture removal strength of the needle also tends to be insufficient. On the other hand, in the production of products such as Chikara-4Tsu, there is a strong tendency to incorporate large amounts of inexpensive inorganic fillers as components of the composition in order to reduce production costs. There is a need for a low-viscosity polymer aqueous dispersion that does not reduce adhesive strength when added with a filler.

[Problem that the invention seeks to solve]

The present invention attempts to solve the following problems encountered by the conventional technology.

(1) Polymer aqueous dispersions produced by conventional manufacturing methods do not have sufficient adhesion to polypropylene/base fabrics, resulting in poor pile adhesion strength (thread removal strength) and peel strength of secondary base fabrics such as carpets. Inferior.

(2) Polymer aqueous dispersions produced by conventional production methods lack the ability to stably mix and disperse large amounts of inorganic fillers, and the adhesion strength decreases significantly due to filler blending.

(3) Polymer aqueous dispersions obtained by conventional production methods lack mechanical stability.

[Means for solving problems]

The present inventors have conducted intensive research to develop a polymer aqueous dispersion that has excellent filler dispersibility, mechanical stability, and formulation stability, and also exhibits excellent adhesion to polypropylene fabrics. A naphthalene sulfonate formalin condensate is prepared using an emulsifier that necessarily contains polyoxyethylene alkyl phenyl ether sulfate represented by the structural formula.
゛ The addition of Mekizoku is extremely effective for the above purpose.

The inventors discovered that a satisfactory aqueous polymer dispersion can be obtained and completed the present invention.

That is, the present invention uses a compound of the following structural formula [■] and naphthalene sulfonate formalin as an essential emulsifier when emulsion polymerizing butadiene, ethylenically unsaturated carboxylic acid, and other ethylenically unsaturated monomers. using a condensate,
The resulting aqueous polymer dispersion was tested using a Marlon-type stability tester (
1. A method for producing an aqueous polymer dispersion, characterized in that the amount of coagulated material produced is 0.02 weight or less based on the solid content weight at a rotational speed of 1000 rpm).

Structural formula [I] [Constitution] Butadiene used in the present invention internally plasticizes the dry film of the polymer water dispersion and gives elasticity to give a preferable texture to the carpet after packing. KiE preferably 1o to 90 heavy view area, particularly preferably 50
-80 parts by weight is used, but if the proportion is less than 10 parts by weight, the elasticity of the film will be insufficient and the texture of the fabric after backing will be stiff, making it unsuitable for practical use. If the amount is 90 parts by weight or more, the strength of the coating will decrease, resulting in a decrease in pile removal strength and secondary base fabric peel strength of carpets and the like.

The ethylenically unsaturated carboxylic acid of the present invention is preferably contained in an amount of 0.5 to 10 parts by weight based on the total monomers, and one or more types may be used. Examples of ethylenically unsaturated carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, and maleic anhydride. It is a necessary component to improve the properties, freeze stability, and dispersibility of the filler, and also to improve the adhesion of the film to the substrate, and if the content is 0.5 parts by weight or less in 100 parts by weight of the total monomers. ,
It is not preferable to use more than 10 parts by weight because it is not effective and the water resistance of the film decreases.

Other ethylenically unsaturated monomers used in the present invention include, for example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, 7' methacrylate, and butyl acrylate. , butyl methacrylate, pentyl acrylate, benzyl methacrylate, hexyl acrylate, hexyl methacrylate, heptyl acrylate, hemethyl methacrylate, octyl acrylate, octyl methacrylate, octadecyl acrylate, octadecyl methacrylate, etc. Acrylic acid alkyl ester and methacrylic acid alkyl ester; ethylene saturated aromatic monomers exemplified by styrene, α-methylstyrene vinyltoluene, chlorostyrene, 2-4-dibromustyrene, etc. Niacryonitrile, methacrylonitrile, etc. unsaturated nitriles; vinyl esters such as vinyl acetate and vinyl propionate; vinylidene halides such as vinylidene chloride and vinylidene bromide; ethylenically unsaturated such as 2-hydroxypropyl acrylate and 2-hydroxyethyl methacrylate; Hydroxyalkyl esters of cargonic acid: ethylenically unsaturated carboxyl esters such as octyl acrylate, glycidyl methacrylate, etc. and amides such as acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N-butoxymethyl acrylamide, and diacetone acrylamide.

These monomers can be used together with butadiene to form the main chain of a polymer or as a functional group component, for example, to form intermolecular crosslinks, and are used to characterize the texture, water resistance, etc. of a carpet. , preferably 0 to 89% of one or more of these monomers per 100 parts by weight of the total monomers.
．． 5 parts by weight are used.

The emulsifier represented by the following structural formula (1) of the present invention is polyoxyethylene alkylphenyl ether sulfate,
n is an integer of 2 to 20, preferably 2 to 5, M FiNa v K t
NH4H"rT, where R represents an alkyl group having 1 to 12 carbon atoms. A specific example is Emar NC (product of Kao Soap Co., Ltd.). This emulsifier is Preferably, 0.5 to 5.0 parts by weight should be added.Also, if this emulsifier is used alone, other emulsifiers such as alkylbenzene sulfonate (Na,
K), sodium lauryl sulfate, etc. If this emulsifier is used in an amount less than 0.5 parts by weight, it is undesirable because the formulation stability at high loading is poor and there is no effect of preventing foaming when added, and if it is added in excess of 5.0 parts by weight, it will be dispersed after polymerization. It is difficult to blend a large amount of filler, which has a high liquid viscosity.

The naphthalene sulfonate formalin condensate of the present invention is a compound represented by the following structural formula [■], where n = 1
Preferably. For example, Disroll SH (product of Nippon Nyukazai@) can be used.

This naphthalene sulfonate formalin condensate is preferably added halfway when the polymerization rate is 5 to 30%. By doing so, it is possible to obtain an aqueous polymer dispersion for backing which has a low viscosity, exhibits little decrease in strength even when a large amount of filler is blended, and has excellent dispersibility. If a dispersant other than the naphthalene sulfonic acid formalin condensate is used, it is impossible to obtain an aqueous polymer dispersion for backing that can contain a large amount of filler.

If this naphthalene sulfonate formalin condensate is added at a polymerization rate of less than 5%, a large amount of coagulum will be generated in the dispersion after polymerization, which is impractical and the polymerization rate will be 3%.
If it is added in excess of 0%, the viscosity of the system will be high and it will be difficult to stably incorporate a large amount of the potash filler, so this is not preferred.

This 7-talene sulfonic acid formalin condensate C, a range of 15 to 5.0 parts by weight of O per 100 parts by weight of the total monomer,
It is preferably used in a range of 0.5 to 1.0 parts by weight. If it is less than 0.5 parts by weight, the viscosity of the system becomes high and it is not possible to incorporate a large amount of filler, and if it is used in excess of 5.0 parts by weight, a large amount of coagulum will be observed in the dispersion after polymerization. It is not practical.

The aqueous polymer dispersion in the present invention is produced by a batch charging emulsion polymerization method under reaction conditions of a reaction temperature of 0 to 100°C and a reaction time of 5 to 15 hours. For example, the above monomer mixture is emulsified and dispersed in water, and a free radical generating catalyst such as K is used.
PS (K2S208), APS ((NH4)2S208
), an aqueous catalyst such as aqueous hydrogen peroxide, or an oil catalyst such as t-butylhydronog-oxide or cumene hydroperoxide, preferably at 50 to 70°C. At this time, these monomers are considered to be solubilized within the micelles of the emulsifier, and the free radicals of the catalyst enter the micelles to initiate emulsion polymerization.

Furthermore, commonly used additives such as chain transfer agents (tertiary dodecyl mercaptan), antioxidants (hindered phenol), ultraviolet absorbers (benzophenone compounds), ethylenediaminetetraacetic acid, etc. are added to the production of polymer aqueous dispersions. There is nothing wrong with using it. The obtained polymer aqueous dispersion has a pH of 3 to 6 and a viscosity of 50 to 300 cps.
However, the pH is preferably adjusted to 8 to 9 with an alkaline substance (sodium hydroxide, potassium hydroxide, etc.).

It is preferable that the solid content of the aqueous polymer dispersion after the emulsion polymerization reaction is adjusted to 50 to 60% by a method such as stripping.

The aqueous polymer dispersion of the present invention conforms to JIS K-6392-4
In the latex produced when a rotating disk with a rotation speed of 1000 ± 20 rpm is pressed against a test container at a constant pressure for 10 minutes using a Marlon type mechanical stability tester (manufactured by Shinsei Sangyo Co., Ltd.) specified in Section 6. The clot content is measured.

The amount of coagulated material produced at this time is 0.02% by weight or less based on the solid content.

That is, coagulation production rate (a): CH, mass of coagulation (g
): VFd, quality of the sample it (g): wr, total solid content of the sample ←): 0.02% by weight in the case of Ta. If the coagulation rate increases, it becomes a filler when used for carpet backing, for example. This is not preferable because it results in a lack of formulation stability, such as oxidation.

〔effect〕

The aqueous polymer dispersion of the present invention obtained in this way has excellent dispersibility when a filler is blended with Daikin, has excellent mechanical stability, and has excellent electrical contact with hydrophobic fibers such as polypropylene, so it can be used as a backing material. It is suitable not only as a base resin for industrial use, but also as a covering agent for adhesives, paper, fibers, plastics, etc. In addition, the production method of the present invention is particularly suitable for butadiene-containing i60! It has the effect of improving the mechanical stability of polymer aqueous dispersions by more than %.

Furthermore, the aqueous polymer dispersion of the present invention exhibits less skinning phenomenon on the liquid surface due to drying during storage, and what is even more surprising is that when the aqueous polymer dispersion of the present invention is blended and a backing composition is used, When manufacturing carpets, blister (
This is an excellent method in that it can prevent the occurrence of boiling inside the adhesive when the adhesive dries, causing the adhesive to partially blow out onto the back surface of the carpet, which seriously impairs the appearance.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples.

Note that "part" and "ch" in each example are based on weight.

Example 1 In a nitrogen-substituted autoclave, 120 parts of ion-exchanged water, 60 parts of butadiene, 35 parts of styrene, and acrylic acid s were added.
m, Sodium alkylbenzene sulfonate (Neoperex F-25 Kao Soap ■m) 1.0 part, Sodium polyoxyethylene alkyl phenyl ether sulfate (Emer #NC1 Kao Soap ■) 1.0 part, Ethylenediaminetetraacetic acid 0.1 1, and 0.5 part of tertiary dodecyl mercaptan were charged, and at a polymerization temperature of 60C, 0.5 part of ammonium persulfate was added to initiate polymerization. Approximately 3 minutes after starting polymerization
After a period of time, the polymerization rate was 15.7%, and the naphthalene sulfonic acid formalin condensate (Disrol SH1 manufactured by Nippon Nyukazai ■) was 0.
．． 5 parts were added to the reaction vessel and reacted until the polymerization rate reached 98% or more. Next, the - was adjusted to 8.7 with potassium hydroxide, and unreacted monomers were removed and concentrated by stripping, resulting in a polymer aqueous dispersion (solid content 50.3%, silk 8.5, viscosity 150 cps). A) was obtained. A stability test of this dispersion (A) revealed that it had excellent stability compared to aggregate O.

Next, using the above aqueous dispersion (A), the formulation shown in Table 1 was carried out to prepare an adhesive compound for carpet backing, and acrylic loop/guile and polypropylene
1400 g per inch for carpet consisting of the following base fabric
(wet), jute was laminated as a secondary base fabric and dried for 10 minutes in a hot air dryer at 140° C. to prepare a carpet. Next, add 5cI of this carpet.
It was cut to a width of rL, and a peeling test for the secondary base fabric and a thread removal test for the acrylic loop and coil were conducted. Blisters were also determined by observing the back side of the carpet. The test results are shown in Table 2.

Table 2 shows that the aqueous polymer dispersions of the examples of the present invention showed good results.

Table 1 (Composition of adhesive compound and glue) Compound solid content 80±1% Viscosity 17000±1100Ocps (B-type rotational viscometer, No. 4 rotor, 12 rpm)
Nopco NXZ (San Nopco Co., Ltd. product) Example 2 Same as Example 1 except that the emulsifier polyoxyethylene alkyl phenyl ether sodium sulfate used in Example 1 was changed to 2.0 parts Solid content 50.0% pH 8 ,3
An aqueous polymer dispersion (B) having a viscosity of 1106 P'' was prepared.A naphthalene sulfonic acid formalin condensate (Isrol SH, manufactured by Nippon Nyukazai ■) was added at a polymerization concentration of 20.3%.

Thereafter, a stability test was carried out in the same manner as in Example 1 except that the polymer aqueous dispersion (B) thus obtained was replaced with the polymer aqueous dispersion (A), a carpet was produced, and the peel strength and peel strength were determined in the same manner. Suture removal strength was measured. The test results are shown in Table 2. From Table 2, it was confirmed that the aqueous polymer dispersion of the present invention showed good results.

Comparative Example 1.2 A polymer aqueous dispersion was obtained in the same manner as in Example 1.2, except that the naphthalene sulfonic acid formalin m compound (r Throl SH1 Nippon Nyukazai ■ product) was not used.

As a result of mechanical stability tests of these aqueous dispersions,
The coagulation fraction production rates were 0.1% and 0.3%, respectively.

Also, using these aqueous dispersions, carpet backing was performed to prepare carpets in the same manner as in Example 1, and various performance tests were conducted.The results are also shown in Table 2.

Comparative Example 3 Polyoxyethylene alkylphenyl ether 5Atr
Emulsion polymerization was carried out in the same manner as in Example 1, except that R salt was not used, to obtain a polymer aqueous dispersion (E) having a solid content of 50.01, a pH of 8.7, and a viscosity of 200 cps.

A carpet was produced in the same manner as in Example 1, except that the thus obtained aqueous polymer dispersion (E) was used, and the peel strength and thread removal strength were measured in the same manner. Second result
Shown in the table. According to Table 2, in Comparative Example 3, the peel strength of the secondary base fabric and the removal strength of the pile were both inferior to 9. In addition, the blending stability was poor, and a blister phenomenon was observed.1 The backing agent of the present invention was used in large quantities. It was confirmed that even when a filler is added, the resin has a stable formulation and high adhesive strength, and is useful as an excellent aqueous polymer dispersion paste resin for backing.

Dispersibility; polymer aqueous dispersion/heavy calcium carbonate = 1
001500 was blended and stirred for 10 minutes, and the stirring state was observed.

Formulation stability: The adhesive compositions based on Table 1 were left in a dryer at 50° C. for two weeks, and changes in viscosity over time were observed.

(Difference of ±5000 cps is defective) Polymerization chamber measurement - Sampled every hour during polymerization, weighed the fil, measured the weight after drying at 110℃ x 1 hour, measured the cine volatile content, and calculated using the formula below. did.

Polymerization rate (→ 100-butadiene amount XTS × 100 Blister judgment; indicates the number of adhesive blowouts per 1ocIrL2 of the back surface of the carpet.

Claims (1)

[Claims] 1. A compound of the following structural formula [I] and a naphthalene sulfonate as an essential emulsifier in emulsion polymerization of butadiene, ethylenically unsaturated carboxylic acid, and other ethylenically unsaturated monomers. using formalin condensate,
The resulting aqueous polymer dispersion was tested using a Marlon-type stability tester (
1. A method for producing an aqueous polymer dispersion, characterized in that the amount of coagulated material produced is 0.02% by weight or less based on the solid weight at a rotational speed of 1000±20 rpm. Structural formula [I] ▲Mathematical formulas, chemical formulas, tables, etc.▼ (n is an integer from 2 to 20, M is Na, K or NH_4R
is an alkyl group of C_1 to C_1_2. )