WO2002050193A1

WO2002050193A1 - Paint formulations in aqueous dispersions comprising a polyarylalkane composition as coalescent agent

Info

Publication number: WO2002050193A1
Application number: PCT/FR2001/004033
Authority: WO
Inventors: Pascal Michaud; Baudoin Duque; Gaëlle YVERT
Original assignee: Atofina
Priority date: 2000-12-19
Filing date: 2001-12-18
Publication date: 2002-06-27
Also published as: FR2818280A1; FR2818280B1; AU2002225092A1

Abstract

The invention concerns paint formulations in aqueous dispersions comprising a polyarylalkane composition such as a mixture of mono- and bis(methylbenzyl)xylenes as coalescent agent optionally associated with a co-solvent selected between 4-hydroxy-4-methyl-2-pentane or 2-methyl-2,4-pentanediol.

Description

PAINT FORMULATIONS IN AQUEOUS DISPERSIONS

COMPRISING A COMPOSITION OF POLYARYLALCANES

AS A COALESCING AGENT

The invention relates to paint formulations in aqueous dispersions comprising a polyarylalkane composition, optionally combined with an organic cosolvent, as a coalescing agent. One of the desired qualities of a paint is that it forms a uniform coating. In order to obtain a suitable film formation, a coalescing agent is incorporated into the paint formulations in aqueous dispersions. One of the most widely used coalescing agents today is 2,2,4-trimethyl-1,3-pentane diol mono-isobutyrate or TEXANOL.

However, currently, the VOC (volatile organic compounds) directive mentions that, for the "thin layer" application, a solvent which has a boiling point above 250 ° C would not be taken into account in the list of VOCs . Thus, TEXANOL, which has a boiling point of 247 ° C, can probably no longer be used as a coalescing agent in paint formulations in aqueous dispersions in view of this directive.

Paint formulations in aqueous dispersions include water, various adjuvants such as dispersant, neutralizer, pigment, bactericide, etc. , a latex which consists of fine polymer particles of 0.05 to 5 μm in diameter dispersed in an aqueous phase and a coalescing agent.

Obtaining a film from an aqueous dispersion paint formulation generally takes place in three stages.

The first is the concentration of latex by evaporation of water or by absorption of this by a porous support. The main effect of this elimination of water is the formation of a thin film of interstitial water between the latex particles which are very close to each other. There is the appearance of capillary forces which will force the particles to continue their approximation.

At this stage, the second stage which is film formation can begin: the latex particles come into contact with each other. others, undergoing deformations. The spherical particles then gradually take the hexagonal shape.

The last step is called coalescence: the macromolecular chains of the different latex particles diffuse from one particle to another: this is interdiffusion. This results in the loss of the hydrophilic membranous frame existing between the juxtaposed particles. It is during this very slow last step that the film acquires its optimal properties, in particular its mechanical properties and resistance to liquids (solvents, water). This film formation essentially depends on the glass transition temperature (Tg) of the polymer. Thus, a given latex will only give rise to good filification if the temperature is higher than the minimum film-forming temperature (TMF), characteristic of a latex. The role of a coalescing agent is therefore to lower the TMF of the treated latex to facilitate filming at low temperatures.

K.R. Walker "Role of coalescing aids in latex paints", (Spec. Publ.

- R. Soc. Chem. (1990), 76 (Add. Water-Based Coat.) Pages 90-105) mentions that aromatic and aliphatic hydrocarbons have low activity as coalescing agents and can also reduce the gloss of the paint.

We have now found a paint formulation in aqueous dispersion comprising water, adjuvants, a latex and at least one coalescing agent, characterized in that the coalescing agent is a polyarylalkane composition chosen from: - the compositions (l) comprising a mixture of products of formula

(AT) :

(AT)

in which n, and n ₂ = 0 or 1 which contains products (A) such as n ^ n. _j ≈O and products (A) such as n ^ n- _j ≈ l and products of formula (B):

(B)

the compositions (II) comprising a mixture of two products (C) and

(D) in which: the product (C) is a mixture of isomers of formula:

(C) with p, and p ₂ = 0.1 and 2, knowing that p _t + p ₂ <3, and

* product (D) is a mixture of isomers of formula:

(D) with p ',, p "., And p ₄ = 0.1 and 2 P ^* _2. P" ₂ . P ₃ and p ₅ ^≈ 0 and 1 knowing that p ', + p ", + p' ₂ + p" ₂ + p ₃ + p ' ₃ + p ₄ + p ₅ <2.

- the compositions (III) comprising a mixture of two products (AD and (A2), such as: * the product (AU is a mixture of isomers of formula:

(A1) with m ₁ and m ₂ = O, 1 or 2 knowing that m, + m ₂ <3, * the product (A2) is a mixture of isomers of formula:

(A2) with q, and q ₂ = O, 1 or 2 knowing that q, + q ₂ ≤ 3, at least one of the compounds (A1) and (A2) comprising an isomer having three benzene rings. the compositions (IV) comprising the two products (A1) and (A2) and, in addition, at least one compound chosen from the following products (E1), (E2) or (E3): * (E1) is an isomer or a mixture of isomers of formula:

(E1) with r '^ r ", and r ₄ = O, 1 or 2 r' ₂ , r" ₂ , r ₃ , r ' ₃ and r ₅ = 0 and 1 knowing that r'., + R ", + r ^* ₂ + r " ₂ + r ₃ + r ' ₃ + r ₄ + r ₅ is less than or equal to 2, R., and R ₂ represent a hydrogen atom; * (E2) is an isomer or a mixture of isomers of the same general formula as (E1), except that R, and R ₂ represent a methyl and the coefficients r are replaced by s and have the same meaning; * (E3) is an isomer or a mixture of isomers with the same general formula as (E1), except that R _t and R ₂ are different and represent a hydrogen atom or a methyl radical and the coefficients r are replaced by t and have the same meaning.

The compositions (I) may contain product (A) with 2 rings, (methylbenzyl) xylene, and product (A) with 3 rings which is designated by bis (methylbenzyl) xylene. This product (A) with 3 cores can be a product such as n., = 1 and n ₂ = 0, a product such as n, = 0 and n ₂ = 1 or a mixture of the latter two. The polyarylalkane composition may also contain products such as n, = 1 and n ₂ = 1. By way of illustration of compositions (I) which can be used according to the present invention, mention will be made of the polyarylalkane composition sold by the company ATOFINA under the name designation JARISOL XX having a weight content of compounds (A) with 2 and 3 aromatic rings greater than 99%. By way of illustration of compositions (II) which can be used according to the present invention, mention will be made of the polyarylalkane composition sold by the company ATOFINA under the designation JARYLEC C100 which consists essentially of 70% to 80% by weight of a mixture of benzyltoluene isomers (product (C), p, = p ₂ = 0) and by 20% to 30% by weight of dibenzyltoluene isomers (product (C), p, = 1, p ₂ =

0 or p, = 0 and p ₂ = D and ditolylphenylmethane (product (D), p ', + p ",

+ p ' ₂ + p " ₂ + P ₃ + P' ₃ + P ₄ + P ₅ = 0).

These compositions can be obtained by methods described in patents EP 136 230-B1, EP 299 867-B1, EP 384 818-B1, EP 500 435-B1 incorporated in the present invention, by reference, which consist in carrying out the chlorination toluene or xylene and then to carry out a Friedel and Crafts type condensation either on toluene or on xylene (mixture of isomers), or on a mixture of toluene and xylene, or on benzene, or on a benzene mixture and toluene. Once the reaction is complete, the unprocessed reagent (s) are removed directly by distillation and then the crude product can be subjected to a dechlorination treatment as described in patent EP 306 398-B1. Thus, for example, the compositions (II) can be obtained by a process described in patent EP 136 230-B1 which consists, in a first step, in reacting chlorine on toluene by radical reaction in the presence of free radical generator at a temperature between 50 ° C and 110 ° C and then in a second step, the reaction product of the first step is subjected to a condensation reaction with toluene in the presence of FeCl ₃ at a temperature between 50 ° C and 100 ° C.

The compositions (I) can be obtained according to a process described in patent EP 500 435-B1 which consists in carrying out the condensation of (methyl) benzyl chloride with xylene in the presence of FeCl ₃ .

Preferably, the polyarylalkane compositions (I) sold by the company ATOFINA under the designation JARISOL XX will be used. According to the present invention, a weight amount of the polyarylalkane composition ranging from 0.5% to 15% and preferably ranging from 1% to 7% relative to the weight amount of latex used will be used.

The polyarylalkane composition has the advantage of greatly lowering the TMF of latexes, in particular styrene / acrylic latexes.

In addition, there is a good application of the paint, without visible appearance of drips.

The recovery time is extended, which allows the film to be touched up without causing irreversible defects. According to the present invention, the polyarylalkane composition can be combined with at least one cosolvent chosen from 4-hydroxy-4-methyl-2-pentanone also called diacetone alcohol (DA) or 2-methyl-2,4-pentanediol called also hexylene glycol (HG).

These cosolvents can be used by weight amounts ranging from 0.5% to 15% and preferably ranging from 1% to 7% relative to the weight amount of latex used.

The association of a cosolvent with the polyarylalkane composition has the advantage of leading to more versatile formulations than with the polyarylalkane composition used alone; especially in the case of purely acrylic latexes.

The following examples illustrate the invention. Products used: Coalescing agents:

- composition of polyarylmethanes (I) having a weight content of (methylbenzyl) xylenes - compound (A) with 2 rings (ni = n2 = 0) and bis (methylbenzyl) xylenes - compound (A) with 3 rings (n1 + n2 = 1 with n1 = 1, n2 = 0; n1 = 0, n2 = 1) greater than 99% sold by the company ATOFINA under the designation JARISOL XX, hereinafter XX, - TEXANOL sold by the company EASTMAN KODAK Cosolvants: - diacetone alcohol, hereinafter DA, sold by the company ATOFINA,

- hexylene glycol, hereinafter HG, sold by the company ATOFINA,

- propylene glycol, hereinafter PG, sold by the company ARCOCHEM.

Latex:

- REPOLEM 2423, hereinafter 2423 which is a styrene / acrylic latex sold by the company ATOFINA,

- ECOCRYL 102, hereinafter E102 which is a pure acrylic latex, sold by the company ATOFINA,

- REPOLEM 2152, hereinafter 2152 which is a styrene / acrylic / acrylonitrile latex sold by the company ATOFINA. LATEX test:

We measured the minimum film-forming temperature - TMF - of latex containing TEXANOL (comparative tests C), XX alone or combined with a cosolvent. Measurement of TMF: The TMF is determined at the lowest temperature where there is formation of a continuous, homogeneous film without cracks according to the international standard ISO 2115 (third edition 1996-02-15). Results:

TABLE 1 In this table, C stands for Comparative.

It can be seen that XX alone makes it possible to considerably lower the TMF of styrene / acrylic and styrene / acrylic / acrylonitrile latexes and therefore has an activity as a coalescing agent equivalent to that of TEXANOL in the case in particular of styrene / acrylic latexes. Combined with a cosolvent, the combination has the same activity as TEXANOL in the case of pure acrylic latexes.

TESTS on paints (gloss paint): Tests carried out with REPOLEM 2423 as latex:

Paint 1 not in accordance with the invention: Quantities used for 1 kg of finished product.

In a 3-liter reactor equipped with a condenser, a stirring device (set to 200 rpm), the following are introduced in order: 19.4 g of water; 28.3 g of propylene glycol (cosolvent); 0.8 g of AMP 90 (neutralizer); 5.2 g of DISPEX GA 40 (dispersant); 207 g of TIPURE R 706 (TiO ₂ ); 0.1 g of ACTICIDE BX (bactericide) and 1.9 g of TEGO FOAMEX 7447 (antifoam).

The preparation is stirred at high speed for 20 min. Then added 547.3 g of REPOLEM 2423; 21.7g TEXANOL (coalescing agent) and again a BYK 024 defoamer (0.9 g); then 54.2 g of RHEOLATE 278 (thickener), and it is made up with 110.9 g of water. When the preparation is homogeneous, the pH is adjusted to 8.5 using ammonia. Painting 2 according to the invention:

The procedure is as above except that TEXANOL is replaced by the same amount of XX and propylene glycol (PG) is replaced by the same amount of hexylene glycol HG.

Paint 3 according to the invention: The procedure is as in the case of paint 2 except that the HG is replaced by the same amount of diacetone alcohol DA.

BRIGHTNESS MEASUREMENT:

The gloss is measured using a gloss meter from 3 different angles depending on the nature of the paint. In our case, since it is a high gloss paint, the viewing angles are 20 to 60 degrees. For a glossy aqueous paint, a gloss value of at least 60%, measured at an angle of 20 degrees, is considered correct.

TEST OF PRACTICAL APPLICATION: THE RESUMPTION: The resumption designates the scar left in a film at the level of the zone of connection between the first part and the second part applied after a given time. In our tests, this time is equal to 2 minutes.

It is a quantitative evaluation of a more or less marked defect which is noted from 1 to 6, 1 representing the best performance and 6 the worst.

The results are reported in Table 2.

TABLE 2

Paints 2 and 3 have a significantly higher gloss than that taken as the reference paint (1 NC) and improved recovery. Tests carried out with the ECOCRYL 102:

The procedure is as for paint 1 except that REPOLEM 2423 is replaced by the same quantity of ECOCRYL 102 and that the quantities of coalescing agents and cosolvents are lower and are as indicated in table 3.

The following practical application tests are carried out on these paints: - recovery,

- the stretch and the sag which make it possible to quantitatively assess the ease of application and the sag of a paint film as well as the more or less pronounced presence of streaks on the film: they are noted, as for the recovery from 1 to 6, 1 representing the best performance and 6 representing the worst.

The results are reported in Table 3.

TABLE 3

In Tables 2 and 3, NC means Not Compliant with the invention. The application performance is significantly improved compared to the 4 NC reference.

Claims

1. Paint formulation in aqueous dispersion comprising water, adjuvants, a latex and at least one coalescing agent, characterized in that the coalescing agent is a polyarylalkane composition chosen from:

- the compositions (I) comprising a mixture of products of formula (A):

(AT)

in which n, and n ₂ = 0 or 1 which contains products (A) such as n ₁ + n ₂ = 0 and products (A) such as n ₁ + n ₂ = 1 and products of formula (B) :

(B)

- the compositions (II) comprising a mixture of two products (C) and (D) in which: * the product (C) is a mixture of isomers of formula:

(C) with p, and p ₂ = 0.1 and 2, knowing that p ₁ + p ₂ <3, and * product (D) is a mixture of isomers of formula:

(D) with p '. ,, p' and p ₄ ≈ 0.1 and 2 p ^* ₂ , p " ₂ , p ₃ and p ₅ = 0 and 1 knowing that p + p", + p ' ₂ + p " ₂ + P ₃ + p ' ₃ + p ₄ + p ₅ <2.

the compositions (III) comprising a mixture of two products (AD and

(A2), such as:

* the product (AD is a mixture of isomers of formula:

(AD with m, and m ₂ ≈ 0, 1 or 2 knowing that n + m ₂ <3,

* the product (A2) is a mixture of isomers of formula:

(A2) with q, and q ₂ ≈ 0, 1 or 2 knowing that q, + q ₂ <3, at least one of the compounds (A1) and (A2) comprising an isomer having three benzene rings. the compositions (IV) comprising the two products (A1) and (A2) and, in addition, at least one compound chosen from the following products (E1) / (E2) or (E3): * (E1) is an isomer or a mixture of isomers of formula:

(E1) with rr ", and r ₄ = 0, 1 or 2 r ' ₂ , r" ₂ , r ₃ , r' ₃ and r ₅ = 0 and 1 knowing that r ', + r ", + r' ₂ + r " ₂ + r ₃ + r ' ₃ + r ₄ + r _s is less than or equal to 2,

R ₁ and R ₂ represent a hydrogen atom; * (E2) is an isomer or a mixture of isomers of the same general formula as (E1), except that R ₁ and R ₂ represent a methyl and the coefficients r are replaced by s and have the same meaning; * (E3) is an isomer or a mixture of isomers of the same general formula as (E1), except that R, and R ₂ are different and represent a hydrogen atom or a methyl radical and the coefficients r are replaced by t and have the same meaning.

2. Formulation according to claim 1, characterized in that the compositions (I) comprise product (A) (n1 = n2 = 0) with 2 rings, (methylbenzyl) xylenes, and product (A) with 3 rings, bis (methylbenzyl) xylenes (ni + n2 = 1 with ni = 1 and n2 = 0 of ni = 0 and n2 = 1).

3. Formulation according to claim 2, characterized in that the composition (1) has a weight content of compounds (A) with 2 and 3 aromatic rings greater than 99%.

4. Formulation according to one of claims 1 to 3, characterized in that one uses a weight amount of the polyarylalkane composition ranging from 0.5% to 15% relative to the weight amount of latex used.

5. Formulation according to claim 4, characterized in that one uses a weight amount of the polyarylalkane composition ranging from 1% to 7% relative to the weight amount of latex used.

6. Formulation according to any one of claims 1 to 5, characterized in that it further comprises a "cosolvent" chosen from 4-hydroxy-4-methyl-2-pentanone (diacetone alcohol) or 2-methyl -2,4-pentanediol (hexylene glycol).

7. Formulation according to claim 6, characterized in that one uses a weight amount of cosolvent ranging from 0.5% to 15% relative to the weight amount of latex used.

8. Formulation according to claim 7, characterized in that one uses a weight amount of cosolvent ranging from 1% to 7% relative to the amount of latex used.