WO2015091901A1

WO2015091901A1 - Aqueous dispersion of a modified resin

Info

Publication number: WO2015091901A1
Application number: PCT/EP2014/078637
Authority: WO
Inventors: Jessie LIN; Cain CHEN; Evan WU
Original assignee: Wacker Chemie Ag
Priority date: 2013-12-22
Filing date: 2014-12-19
Publication date: 2015-06-25
Also published as: CN104726021A; CN104726021B

Abstract

This invention relates to an aqueous dispersion of silicone modified polyester resin comprising a dispersing agent containing structural units of formula (I) wherein R₁ and R₃ in each occurrence may be the same or different and are divalent C₁-C₂₀ hydrocarbon groups, preferably divalent C₁-C₃ hydrocarbon groups; more preferably C₁-C₃ alkylene radicals; R₂, R₄ and R₅ are H atom or C₁-C₂₀ hydrocarbon groups, preferably R₂ and R₄ are H atom or C₁-C₃ alkyl radicals, preferably R₅ is C₁-C₃ alkyl radical; M is OH, ONa, OK or R₆OH, wherein R₆ is C₁-C₄ alkylene radical; preferably M is OH; m and n are positive integer; the value of m/ (m+n) is between 0.4 and 0.99, preferably between 0.75 and 0.95, and more preferably between 0.85 and 0.92. It can be widely applied in the coating field.

Description

Aqueous Dispersion of a Modified Resin

Technical Field

This invention involves an aqueous dispersion of modified resin. It can be widely applied in the coating field.

Technical Background

Silicone modified resins have wide applications, especially in the coating field. They can be used in heat-resistant coatings, powder coatings, weather-resistant protective coatings, H level insulation paints, sealing coatings for electronic components, impregnated glass cloths, glass tube coatings, wire enamel coatings and metal coil coatings.

The modification methods of silicone modified resins include physical blending methods and chemical copolymeri zation methods. Products obtained via the physical blending methods are subject to the micro-phase separation, which impairs the mechanical hardness. In chemical modifications, organic resins are added to the backbone end or side chain of silicone through condensation, free radical polymerization or addition reaction, forming block copolymers, graft copolymers or interpenetrating network polymers. Or the condensation reactions can happen between the silane or siloxane containing hydroxyl groups or alkoxy groups, and the polyester resins with low molecular weight or their intermediate products containing hydroxyl groups or alkoxy groups (with the catalysts) .

Reactions between silicones and resins can occur in solution in advance, as well as in the film formation. When using silicone intermediates to modify other organic resins in the coating industry, the concentration of the silicone intermediates in the final products is normally around 5-80wt%. If the concentration is lower than 10wt%, the modification effect will not be so obvious. If the concentration is higher than 50wt%, the cost will be too high. The varieties of the silicone modified resins mainly include the silicone modified alkyd resins, polyester resins, polyacrylic ester, epoxy resins and polyurethane . However, the present products of the silicone modified polyester resins are mainly based on organic solvent and the concentration of solvent could be 40wt~6 or even more, of which the production and application process has adverse influence on environment and the health of the product line personnel .

Invention Descriptions

This invention accidently discovered an aqueous system of silicone modified polyester resin, which possesses multiple advantages, including a wide adjustable range of solid content, a simple production process, high stability and environment- friendliness .

The technical protocols to achieve the invention goals can be concluded as below:

An aqueous system of silicone modified polyester resin, comprising a dispersing agent containing structural units of formula (I)

wherein Ri and R3 are divalent C1 - C20 hydrocarbon groups, preferably divalent C1-C3 hydrocarbon groups; more preferably C1-C3 alkylene radicals;

R2 , R₄ and R5 are H atom or C1 - C20 hydrocarbon groups, preferably R2 and R₄ are H atom or C1-C3 alkyl radicals, preferably R5 is C1-C3 alkyl radical;

M is OH , ONa, OK or ReOH , wherein R6 is C1-C4 alkylene radical; preferably M is OH ;

m and n are positive integer; the value of m/ (m+n) is between

0.4 and 0.99, preferably between 0.75 and 0.95, and more preferably between 0.85 and 0.92.

The aqueous system above, wherein said dispersing agent dosage is between 0. lwt% and 20wt%, preferably between 0.5wt% and 10wt%, and more preferably between lwt% and 6wt%, based on the whole aqueous system.

The aqueous system above, wherein the Mw molecular weight of said dispersing agent is between 5,000 and 200,000 g/mol, preferably between 20,000 and 150,000 g/mol.

The aqueous system above, wherein the viscosity of 4wt% water solution of said dispersing agent at 20°C is 1-50 mPa-s, preferably 4-40 mPa-s, and more preferably 4-30 mPa-s.

The aqueous system above, wherein said dispersing agent containing at least a kind of polyvinyl alcohol. The aqueous system above, wherein alcoholysis degree of said Polyvinyl alcohol is 40-99% (mol/mol) , preferably between 75% and 95% (mol/mol) , and more preferably between 85% and 92% (mol/mol) . The aqueous system above, wherein the dispersing agent is the combination of 2 or more kinds of polyvinyl alcohol with different alcoholysis degrees.

The aqueous system above, wherein water is the continuous phase, water content is between 15wt% and 90wt%, preferably between 30wt% and 70wt%, based on the whole aqueous system.

The aqueous system above, wherein solid content is between 10wt% and 85wt%, preferably between 20wt% and 50wt~6 , more preferably between 30wt% and 45wt%.

The aqueous system above, wherein the aqueous system is suspension or emulsion; preferably an emulsion with particle size between 200nm and 2000nm and the particle size span of 1.2-2.4; more preferably an emulsion with particle size between 300nm and 1500nm and the particle size span of 1.2-2.4.

The aqueous system above, wherein the acid number of said silicone modified polyester resin is 0.2-50 mg KOH/g, preferably 2.5-25 mgKOH/g.

The aqueous system above, wherein said silicone modified polyester resin is the product resulting from the reaction between polyesters and silicone intermediates which containing alkoxy and / or hydroxyl reactive groups. The aqueous system above, wherein the silicone content is 5- 80 wt% based on the silicone modified polyester, prefer 15- 60wt%, more prefer 15-40wt%.

The aqueous system above, wherein silicone modified polyester resins are resulted from polyester resins modified by silicone intermediates containing active groups of alkoxy groups and/or hydroxyl groups.

As the aqueous system said above, which can be characterized in that the oil phase is incontinuous and may contain, but not limited to esters, ketones, alkanes, alcohol ethers and/or alcohol-ether-esters and/or dibasic esters or the mixture thereof; including ethyl acetate and butyl aetate; including dibasic esters mixtures of dimethyl succinate, dimethyl glutarate and dimethyl adipate; including acetone, butanone, cyclohexanone ; including aromatic hydrocarbons, butyl cellosolve, butyl alcohol; including alcohol-ether-esters of ethylene glycol series, alcohol-ether-esters of propylene glycol series; preferably including ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol methyl ether propionate, di (propylene glycol) methyl ether acetate, ethylene glycol monoethyl ether acetate, di (2-ethoxyethoxy) ethyl acetate, 2-butoxyethyl acetate and di (2-butoxyethoxy) ethyl acetate.

The products of the silicone modified polyester resins could be either solid or liquid. The solid silicone modified polyester resins should be dissolved in the solvents in advance, forming even phase solution. Normally, high concentration solution with less solvent is preferred. Add the silicone modified polyester resin solution and appropriate amount of nonionic emulsifiers into the reaction kettle, mix well by stirring under the room temperature, add water into the reaction kettle while stirring, add appropriate amount of preservatives, and the aqueous system in this invention is obtained. In some conditions, appropriate amount of water should be added to the mixture of the silicone modified polyester resin solution and nonionic emulsifiers during their mixing stage.

The solid content of the aqueous system in this invention is characterized in that measure 2 + 0.2 g of sample into the petri dish with the diameter of 75 mm, desiccate for 30 minutes at the temperature of 15012 °C and the solid content is the weight ratio of the obtained solid materials compared to the initial aqueous system.

The aqueous system in this invention should meet the stability requirement of: in the 6-month static storage period under the room temperature, simple mechanical stirring could re-disperse it to the fluids suitable for industrial production.

A Preferred emulsion from the invention aqueous system meets the stability requirement of: in the 2weeks static storage period under50°C, the emulsion is not breaking, wherein the diameter of the emulsion is 200nm-200 Onm; prefer 300nm-1500nm with span of 1.2-2.4.

The silicone modified polyester resins are the reaction products of the polyester resins or polyester intermediates containing alkoxy groups and/or hydroxyl groups, and the intermediate products of silicone containing alkoxy groups and/or hydroxyl groups, with or without using catalysts. This reaction is the co-condensation method well known by technicians in this field. As for typical preparation method, please refer to the content on the polyesters modified silicone resins in Chapter 8.4.2 of "Synthesis Technology and Products Application of Silicone Products" by Guoqiao Lai, Songmin Xing, Chemical Industry Press, May 2010, Second Edition.

The acidic values of the silicone modified polyester resins suitable for this invention should be 0.2-50 mgKOH/g, preferably 2.5-25 mgKOH/g.

The preferred silicone intermediates for modification are those containing silanol group (containing the functional group of Si-OH) and/or Si-alkoxy group (containing the functional group of Si-OR) , including one or more of M unit, D unit, T unit and Q unit.

R⁷ _aR⁸ _bSiOi_/2 M unit

S1O4/2 Q unit

R⁷ and R⁸ represents carbon-hydrogen groups of CI- C20, respectively, optionally mixed with heteroatom linking groups, including but not limited to:

o o o

ft II II

,Q , >s , — XH— -,—C—0—~,—O— _'0—0— ·—O—S—O—

o o o o o

II ll li li „ !I

—o—p—o— ,—ø—s—o—>—m—c—- .—m—c—o— —MI—c—w

II

o

a is an integer among 0, 1, 2 or 3, preferably 0, 1 or 2 ;

b is an integer among 0, 1, 2 or 3, preferably 0, 1 or 2; In M unit, a+b=3,

in D unit, a+b=2, and

in T unit, a+b=l .

R⁷ and R⁸ represents preferably alkyl group of C1-C18, aryl group of C6-C20, aryl alkyl group of C7-C18, cycloalkyl group of C5-C12, C2-C18 alkenyl group, diol group, epoxy group (the oxygen atoms don't connect directly to the silicon atoms), alkoxy group of C1-C18, unsaturated alkyl group of C2-C20 (like vinyl, allyl, propenyl, isopropenyl group) , and the terminal C4-C18 groups of alkenyl, alkynyl, and vinyl ether and allyl ether group. More preferably, R⁷, R⁸ represents methyl, ethyl, vinyl, allyl, methoxy, and ethoxy and phenyl group, respectively .

The molecule may contain or form silsesquioxane and poly- phenyl silsesquioxane and/or poly-methyl silsesquioxane, which consist of T units.

These intermediate products of silicone can be terminated by regular terminal groups, such as one or more of trialkylsilyl, dialkylsilanol , dialkylalkoxysilyl, alkyl dialkoxysilyl , trialkoxysilyl , dialkylvinylsilyl , triaryl silyl, diarylsilanol , diarylalkoxysilyl, aryl dialkoxysilyl, diarylvinylsilyl .

The preferred of silicone intermediates are methoxy phenyl /methyl silicone resins, among which the mole ratio of phenyl vs. (methoxy and alkyl) is (0.5-2) :1, preferably (0.5-1.5) :1, even more preferably (0.8-1.2) :1. The phenyl content in the resin is 20-50wt%. The silicone intermediates could be the liquid or solid silicone resins under the room temperature. The commercial silicone resins suitable for this invention include: SILRES® SY 231,SILRES® SY300, SILRES® IC 232, SILRES® IC 368, SILRES® IC 678, SILRES® IC 836, Shin-Etsu KR211, KR212, KR214, KR216, Dow Corning Z 6018, Dow Corning 3037, Dow Corning 233, Dow Corning 249 or Dow Corning 3074.

In the silicone intermediates, the alkoxy groups are normally 15-18 wt% of the intermediates and the hydroxyl groups are normally 3-6 wt% of the intermediates. The higher content of alkoxy and/or hydroxyl groups means stronger reactive activity with polyester.

The polyesters in this invention are the hetero chain macromolecular compounds with many carboxylic ester groups as their backbone components. They are different from other ester- containing polymers with carboxylic ester groups as their backbone side chains, such as cellulose, polyacrylic and polyvinyl esters. The polyester resins in this invention are preferably the polyester resins containing ester groups in both main and side chains.

The preferable polyesters in this invention can be obtained through the condensation between the dibasic or polybasic carboxylic acids or their functional derivatives, and the dibasic or polybasic alcohol/phenols.

The proper polyesters can be regularly synthesized by carboxylic acids (or their acid anhydride) containing 2 or more acidic functional groups, and alcohols containing 2 or more hydroxyl functional groups. The examples of the proper carboxylic acids (anhydride) containing multiple functional groups include: succinic acid (anhydride), glutaric acid (anhydride), benzene-1 , 2 , 4-tricarboxylic acid, phthalic acid (anhydride) , tetrahydrophthalic acid (anhydride) , hexahydrophthalic acid (anhydride), inner bicycle-2 , 2 , 1-5- enanthine-2 , 3-dicarboxylic acid, tetrachlorophthalic acid (anhydride) , cyclohexanedicarboxylic acid, isophthalic acid, terephthalic acid, azelaic acid, maleic acid (anhydride) , trimesic acid, 3, 6-dichlorophthalic aicd, tetrachlorophthalic aicd, adipic acid and sebacic acid. The examples of the proper alcohols containing multiple functional groups include: glycerol, trimethylol propane, pentaerythritol , ethylene glycol, diethylene glycol, propanediol, 1 , 3-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, heptanediol, hexanediol, octanediol, 2-butyl-2-ethyl-l , 3-propanediol , neopentyl glycol, trimethyl pentanediol, Cyclohexanedimethanol.

It depends on the mole ratio of -COOH/-OH in monomers mixture whether the polyester mainly contains carboxylic acid functional groups of -COOH or hydroxyl functional groups of - OH. In most cases, polyester suitable for this invention are basically the straight chains with 2 or more hydroxyl or carboxylic acid functional groups, or the side chains with more than 2.5 hydroxyl or carboxylic acid functional groups. Under more cases, the polyesters with various structural units are suitable. Examples :

Without specific instructions, all the percentage is based on weight to weight.

PVA 0588, provided by Wacker: According to DIN 53015, the viscosity of 4% water solution of it is 5 mPa-s at 20°C. It is PVA with the alcoholysis degree of 88%. Dissolve it to 20 wt% water solution before use.

PVA 0488: According to DIN 53015, the viscosity of 4% water solution of it is 4 mPa-s at 20°C. It is PVA with the alcoholysis degree of 88%. Dissolve it to 20 wt% water solution before use.

PVA1388: According to DIN 53015, the viscosity of 4% water solution of it is 13 mPa-s at 20°C. It is PVA with the alcoholysis degree of 88%. Dissolve it to 11 wt% water solution before use.

PVA2588: According to DIN 53015, the viscosity of 4% water solution of it is 25 mPa-s at 20°C. It is PVA with the alcoholysis degree of 88%. Dissolve it to 10 wt% water solution before use.

PVA 117: According to DIN 53015, the viscosity of 4% water solution of it is 29 mPa-s at 20°C. It is PVA with the alcoholysis degree of 99%. Dissolve it to 10 wt% water solution before use.

PVA 141, provided by Wacker: It is PVA with the alcoholysis degree of 41%. Dissolve it together with PVA 117 at specific rations and form 10 wt% water solution before use. Table 1

Silicone modified polyester A (SMP A) with 75wt% solid content is provided by Eternal Chemical. The content of methoxy methyl / phenyl modified silicone is 30wt% based on the silicone modified polyester. Propylene glycol monomethyl ether acetate (PMA) is used as solvent. Raw materials for the synthesis of polyester part of SMP A are: neopentyl glycol, 2- Butyl-2-ethyl-l, 3-propanediol, phthalic anhydride, isophthalic acid, and terephthalic acid. The acid value of SMP A is 2.9 mg KOH/g, Molecular weight M_w is between 15000 and 17000, Mw/Mn is 6, obtained by GPC test while using polystyrene standard and THF solvent and the hydroxyl value is 25-500 mg KOH/g.

The solid contents of SMP A emulsion in examples 1-4 is in the range of 40wt-45wt%.

The preparation process is: put dispersing agent (PVA 0588, PVA 0488, PVA 1388, or PVA 2588) and SMP A into the vessel, stir until uniform, and water is added into the vessel step by step along with stirring. Then preservative is added into the vessel. The particle sizes of the final emulsion products in example 1-4 are listed in the above Table 1.

In another process of decreasing solvent content in emulsion products, solvent would be evaporated at the beginning: Put SMP A solution into the vessel, vacuum the vessel under certain temperature and stirring. After certain time, the concentrated SMP solution is added to the vessel, and then dispersing agents are added under stirring. When the system becomes homogenous, add water and preservatives to the vessel step by step. Emulsion with lower solvent content and higher solid content could be prepared by this way.

Table 2

According to example 5-8, water—in—oil SMP emulsion with the solid content of 30%-45wt% could be obtained.

Silicone modified polyester B (SMP B) with 60% solid content is provided by Eternal Chemical. The content of methoxy methyl / phenyl modified silicone is 15wt% based on the silicone modified polyester. Raw materials for the synthesis of polyester part of SMP B are: neopentyl glycol, terephthalic acid, and phthalic anhydride. The acid value of SMP B is 5.5 mg KOH/g, and the hydroxyl value is 25-500 mg KOH/g.

Table 3

Euxyl K 320 is the mixture of 2-phenoxyethanol, methyl 4- hydroxybenzoate and ethyl-4-hydroxybenzoate . It provided by Schuelke .

Table 4

Silicone modified polyester C (SMP C) with solid content 60wt% is provided by Eternal Chemical. The content of methoxy methyl / phenyl modified silicone is 30wt% based on the silicone modified polyester. Raw materials for the synthesis of polyester part of SMP C are: bisphenol A, polyoxyethylene ether, neopentyl glycol, and terephthalic acid. The acid value of SMP C is 19.3 mg KOH/g, and the hydroxyl value is 25-500 mg KOH/g.

Dissolve SMP C in the PMA solution and get 60 wt% SMP C solution. Add SMP C into the vessel which contains PVA 1388 dispersing agent slowly, stir until homogenous, and then add water to the vessel along with stirring. By adding preservatives into the vessel, final emulsion with white appearance could be obtained. The emulsion is a little break-up at 50°C oven for 1 week. But it would be re-dispersed and become uniform emulsion by simple stirring, which is still suitable for industrial production and meet the stability standard in the invention.

Table 5

Add dispersing agents (PVA 141 and PVA 117 solution, and PVA 2588 solution) to the vessel, dose SMP A solution slowly to the vessel along with stirring. When the system forms homogenous white cream, water is added slowly to the vessel under stirring. By adding certain amount of preservative, final emulsion with white appearance is obtained. The emulsion is a little break-up at 50°C oven for 1 week. But it would be re- dispersed and become uniform emulsion by simple stirring, which is still suitable for industrial production and meet the stability standard in the invention.

Coating samples are prepared by using emulsion products from example 1 and 2.

Table 6

Under the room temperature, evenly coat the product of each

Coating examples with 80-ym wire bar coaters on experimental aluminum plates (A-36) provided by Q-Lab. The dried coating thickness is about 20-30ym (dry the film after curing and the curing condition is 150°C for 15 minutes) .

Measure the gloss degree using the gloss meter and observe the yellowing degree, obtaining the test data as below:

Coating sample 1 and 2 pass the Pencil Hardness test of 2H. The particle diameter measurement used in this invention is Malvern Mastersizer 2000.

The particle diameter in this invention is obtained

according to the laser diffraction spectroscopy. The volume based particle diameter is based on following formula (p=4, q=3)

x(P, Q) = x (4, 3) = (

The span of the particle size distribution in this invention is defined as (D90-D10) /D50.

D50 is defined as the value of the particle diameter at 50% in the cumulative distribution. For example, if D50=0.68 ym, then 50% of the particles in the sample are larger than 0.68 ym, and 50% smaller than 0.68 ym. D10 or D90 is defined as the value of the particle diameter at 10% or 90% in the cumulative distribution respectively. For example, if D10=0.1 ym, then 10% of the particles in the sample are smaller than 0. lym, if D90=l ym, then 90% of the particles in the sample are smaller than lym.

The hardness test instrument used in this invention is "Scratch Hardness Tester Model 291" manufactured by Erichsen and the hardness is measured according to the Standard of

IS015184. The gloss meter used in this invention is "LZM151" manufactured by Erichsen and the gloss is measured according to the Standard of IS02813. The data listed in the table are the measurement results at 60°. The colorimeter used in this invention is "Color Guide 45/0"manufactured by BYK Gardner and the measurement is based on the Standard of GB/T11186.1-89.

Claims

Claims :

1. An aqueous system of silicone modified polyester resin comprising a dispersing agent containing structural units of formula (I)

wherein Ri and R3 are divalent C1 - C20 hydrocarbon groups, preferably divalent C1-C₃ hydrocarbon groups; more preferably C1-C₃ alkylene radicals;

R2 , R₄ and R5 are H atom or C1 - C20 hydrocarbon groups, preferably R2 and R₄ are H atom or C1-C₃ alkyl radicals, preferably R5 is C1-C₃ alkyl radical;

m and n are positive integer; the value of m/ (m+n) is between 0.4 and 0.99, preferably between 0.75 and 0.95, and more preferably between 0.85 and 0.92.

2. An aqueous system as claimed in claim 1, wherein said dispersing agent dosage is between 0. lwt% and 20wt%, preferably between 0.5wt% and 10wt%, and more preferably between lwt% and 6wt%, based on the whole aqueous system.

3. An aqueous system as claimed in claim 1 or 2, wherein the Mw molecular weight of said dispersing agent is between 5,000 and 200,000, preferably between 20,000 and 150,000.

4. An aqueous system as claimed in claim 1, 2 or 3, wherein the viscosity of 4wt% water solution of said dispersing agent at 20°C is 1-50 mPa-s, preferably 4-40 mPa-s, and more preferably 4-30 mPa-s.

5. An aqueous system as claimed in any of claims 1 to 4, wherein said dispersing agent containing at least a kind of polyvinyl alcohol.

6. An aqueous system as claimed in claim 5, wherein alcoholysis degree of said polyvinyl alcohol is 40-99%

(mol/mol) , preferably between 75% and 95% (mol/mol) , and more preferably between 85% and 92% (mol/mol) .

7. An aqueous system as claimed in any of claims 1 to 6, wherein water is the continuous phase, water content is between

15wt% and 90wt%, preferably between 30wt% and 70wt%, based on the whole aqueous system.

8. An aqueous system as claimed in any of claims 1 to 7, wherein the aqueous system is an emulsion; preferably an emulsion with particle size between 200nm and 2000nm and the particle size span of 1.2-2.4; more preferably an emulsion with particle size between 300nm and 1500nm and the particle size span of 1.2-2.4.

9. An aqueous system as claimed in any of claims 1 to 8, wherein the acid number of said silicone modified polyester resin is 0.2-50 mgKOH/g, preferably 2.5-25 mgKOH/g.

10. An aqueous systemAccordingas claimed in any of claims 1 to 9, wherein said silicone modified polyester resin is the product resulting from the reaction between polyesters and silicone intermediates which containing alkoxy and / or hydroxyl reactive groups.