KR101312909B1 - Water-soluble One Composition Type of Paint and Varnish for Polyolefin Plastics Having Excellent Chemical Resistance - Google Patents

Abstract

The present invention relates to a water-soluble one-component coating composition for polyolefin-based plastics excellent in chemical resistance. In particular, by adding silane to the coating composition consisting of a non-polar polyolefinene resin and a polar styrene-acrylic resin to further increase the crosslinking degree of the coating film, the chemical resistance of the coating film is further improved to reduce discoloration and peeling of automobile interior materials. It is about the water-soluble one-component coating composition for polyolefin type plastics which has an effect.

Description

Water-soluble One Composition Type of Paint and Varnish for Polyolefin Plastics Having Excellent Chemical Resistance}

The present invention relates to a water-soluble one-component coating composition for polyolefin-based plastics. In particular, the present invention relates to a water-soluble one-component coating composition for polyolefin-based plastics which can be applied to polyolefin-based plastic interior materials of automobiles and can reduce discoloration and peeling of interior materials.

Generally, the non-polar type polypropylene plastic resin paint uses a solvent type paint or water-soluble acrylic paint with pretreatment such as primer or flame treatment.

The water-soluble acrylic paint resin usually uses an emulsion resin, but the emulsifier used when preparing the emulsion resin degrades the water resistance and chemical resistance of the coating film. That is, when the reactive emulsifier that is chemically bonded to the particle surface is stabilized, the emulsifier is not separated by water, but the wettability and pigment dispersibility are inferior due to the low emulsifier dissolved in the water layer and the high surface tension of the paint. Occurs.

In order to improve such water resistance and chemical resistance, a method of using an emulsifier in preparing an emulsion resin, using a hydrophobic monomer instead of an emulsifier, or applying a coating film crosslinking agent such as a silane coupling agent is known.

However, when the hydrophobic monomer is used instead of the emulsifier, the chemical properties are improved, but there is a problem that the adhesion of the polar material is lowered.

In addition, when a coating film crosslinking agent such as a silane coupling agent is applied, reemulsification of the surfactant due to contact between the coating film and water may be prevented, but when the silane coupling agent is applied, the paint may be gelled due to a linear reaction with the resin during storage. do.

Accordingly, an object of the present invention is to provide a water-soluble one-component coating composition for polyolefin-based plastics for improving chemical resistance of plastic interior materials of automobiles.

The above object is a water-soluble one-component coating composition for polyolefin plastic according to the present invention, 30 to 50% by weight of chlorinated polyolefin-based water-soluble emulsion resin; Acrylic styrene-based copolymer water-soluble emulsion resin containing two epoxy-based epoxy crosslinking agents 10 to 20% by weight of propylene glycol solvents; 25-35 weight percent of ion-exchanged water; And 0.1 to 3 weight percent of silane.

Hereinafter, the present invention will be described in more detail.

In the present invention, the chlorinated polyolefin-based water-soluble emulsion resin is preferably used a chlorinated polypropylene or polyethylene resin having a chlorination degree of 10 to 70%.

The polyolefin water-soluble emulsion resin content is contained in 30 to 50% by weight of the total coating composition. If the content is less than 30% by weight is less effective in improving the moisture-proof effect, in particular the folding effect of moisture-proof, if it exceeds 50% by weight is not economical because the improvement effect is not so large.

In the present invention, the acrylic-styrene copolymer of the acrylic-styrene copolymer-soluble water-soluble emulsion resin containing the epoxy-based crosslinking agent having two epoxy groups has a number average molecular weight of 6,000 to 100,000 by copolymerizing an acrylic monomer with styrene. And, the glass transition temperature is in the range of 25 to 75 ℃, the solid content is prepared to be 20 to 50% by weight.

The styrene component used is styrene, or a derivative thereof, and the acrylic component used may be selected from at least one of acrylic groups such as acrylic acid, methacrylic acid, methylmethacrylic acid, and acrylonitrile. .

The copolymer is very preferably adjusted to the glass transition temperature by appropriately adjusting the content ratio of the monomers, if the glass transition temperature is less than 25 ℃ flexible because it is difficult to dissociate because the resistance to shear force is difficult to dissociate When the blocking phenomenon occurs, and the temperature exceeds 75 ° C, the polymer forming the coating layer is very weak against impact, which is advantageous for dissociation, but inferior in moisture resistance at folding.

The polymer preferably contains 0.005 to 5% by weight of an epoxy-based crosslinking agent having two epoxy groups. The crosslinking agent easily penetrates into the particle surface of the polymer, so that the crosslinking occurs well, and the absorption rate and gel strength are greatly increased. It can provide an effect of improving.

As such, the acrylic-styrene copolymer-soluble water-soluble emulsion resin containing two epoxy-based epoxy crosslinking agents is 0.1 to 2.0 based on the copolymer of an epoxy crosslinking agent having two epoxy groups in methanol (eg, glycerol polyglycidyl ether). It is prepared by adding the weight%, adding the styrene-acrylic copolymer to the mixture, refluxing, washing with methanol, and drying.

In the present invention, the propylene glycol solvent is for dissolving the water-soluble resin, specifically, at least one selected from the group consisting of propylene glycol alkyl ether, propylene glycol alkyl ether acetate, and propylene glycol alkyl ether acetate Can be used.

The content of the propylene glycol solvent is preferably contained in 10 to 20% by weight based on the total coating composition. If it is used below 10% by weight, undissolved resins are produced, and when used above 20% by weight, it is uneconomical because no significant crosslinking occurs due to the excess use.

In the present invention, the ion-exchanged water is added together with the propylene glycol solvent to facilitate dissolution of the resin and to adjust the viscosity of the entire coating composition as appropriate. Used in the range of 25 to 35% by weight has the dissolution activation of the resin and significant coating film viscosity.

In the present invention, the silane is added to further increase the degree of crosslinking of the resin, preferably vinylethoxysilane, vinylmethoxysilane, gamma methacryloxypropyltriethoxysilane, and gamma methacryloxypropyltri At least one is selected from the group consisting of methoxysilane.

The amount of the silane is used in 0.1 to 3% by weight based on the total coating composition. If it is less than 0.1 wt%, the desired level of crosslinking cannot be achieved, so that there is no effect of improving physical properties. If it exceeds 3 wt%, paint storage and work appearance are poor.

In addition, in the coating composition of the present invention, conventional pigments and additives known in the art can be used as necessary. The additive that can be used is not particularly limited, but is preferably 0.1 to 0.5 parts by weight of wetting agent, 0.1 to 0.5 parts by weight of pH adjuster, 2-3 parts by weight of silica-based quencher, and coating film formation based on 100 parts by weight of the total coating composition. 10 to 20 parts by weight, antifoaming agent 0.1 to 1 part by weight, light stabilizer 0.1 to 1 part by weight, medium to weight 1 to 2 parts by weight and / or coloring pigment 1 to 10 parts by weight.

Hereinafter, the present invention will be described in detail with reference to Examples, as follows, of course, the present invention is not limited by the Examples.

< Manufacturing example  1> Chlorination Polyolefin series  receptivity emulsion  Produce

A nickel alloy steel reactor having an inner diameter of 300 mm, a height of 600 mm, and a volume of about 35 liters was prepared. The reactor is surrounded by a heating oil jacket on the outside and is vertically equipped with a ribbon mixer driven at 60-90 rpm inside. The outlet of the reactor is connected to the inlet of a methanol glass bottle in three absorption glass bottles (20 l each) in the order of methanol, water and caustic soda in series. 6 kg of high density polyethylene (Korean Emulsion E308), linear low density polyethylene (Hanyang Chemical DGM1810), or polyolefin (50-200 mesh) selected from polypropylene (Honam Oil Refinery H550), free radical generating aid 30-60 g, talc 3-12 kg and 0.6-1 kg of NaCl were respectively added, and nitrogen gas was passed through the reactor at 50 L / min for 1 hour while the reactor was heated to 50-65 ° C. Subsequently, the first stage chlorination reaction was started by passing chlorine gas at a rate of 20 L / min at 50 ° C. The temperature was raised to 150 ° C. while adjusting the amounts of nitrogen and chlorine gas, and proceeded to step 3-4. In the first and second stages, ultraviolet rays with a wavelength of 3000-4000 조사 were irradiated. The HCl generated as a result of the chlorination reaction was first absorbed into methanol, and then the remaining HCl was absorbed in the order of water (distilled water) and caustic soda.

HCl-absorbed methanol was mixed with 500 ml of 10% ZnCl ₂ solution and 20 ml of concentrated sulfuric acid and then heated to 80-110 ° C. with stirring. At this time, methyl chloride (or ethyl chloride) gas is absorbed into 15 kg of trichloroethylene (TCE) in a 20 liter glass bottle maintained at -15 to -20 ° C to measure the weight increase, and gas chromatography The amount of methyl chloride (or ethyl chloride) as a by-product was calculated by measuring the concentration of methyl chloride (or ethyl chloride). The chlorine concentration in the chlorinated polyolefin was calculated by passing the sample through a glass tube, passing oxygen, absorbing it in a 20% KOH solution while heating to 350 ° C, burning it, decomposing hypochlorite with K ₂ CrO _4, and then titrating with AgNO ₃ solution. The results were 45.5%, 44.5%, and 62.2%, respectively.

< Manufacturing example  2> epoxy Crosslinker  Contained acrylic Styrene-based  Copolymer Water Soluble Emulsion Preparation

To 150 g of water, 20 g of styrene, 30 g of acrylonitrile, 20 g of butylacrylate, 16 g of methacrylic acid, and 14 g of 2-hydroxyethyl methacrylate, sodium dodecylbenzene sulfonic acid was used as an emulsifier and potassium persulfate was used as a polymerization catalyst. To prepare a water-soluble emulsion of styrene-acrylic copolymer having a glass transition temperature of 35 ℃, 40% solids.

10 wt% of a glycerol polyglycidyl ether epoxy crosslinking agent was added to methanol based on the polymer, and the styrene-acrylic copolymer obtained above was added to the mixed solution and reacted at 70 to 85% for 1 to 2 hours. After crosslinking, the mixture was washed with methanol, filtered, and then dried at 90 to 175 캜.

< Example  1 to 4, comparison Example  1> Preparation of Water Soluble Paint

The components and contents used in the preparation of the water-soluble paints of Examples 1 to 4 and Comparative Example 1, respectively, are shown in Table 1 below.

Depending on the presence or absence of the silane, and divided into Examples and Comparative Examples, the coating composition having a content as shown in Table 1 was uniformly mixed with a supermixer. Then, the resin was cooled and pelletized while extruded at 235 ° C. and 280 rpm using a coaxial twin screw extruder while passing water.

ingredient Usage Example 1
(g) Example 2
(g) Example 3
(g) Example 4
(g) Comparative Example 1 (g) Production Example 1 Main resin 40 45 50 45 45 Production Example 2 Auxiliary resin 5 0.1 5 0.1 5 Ion-exchange water Resin dissolution 25 31 31 35 31 Mixed solvent ^{1 ) *} Resin dissolution 10 15 20 15 20 TEGO 2802 ²⁾ Wetting agent 0.3 0.3 0.3 0.3 0.3 Dibutyl ethylamine (DMEA) ³⁾ pH adjusting agent 0.4 0.4 0.4 0.4 0.4 WETLINK 78
Silane ^{4 )} Cross-linking agent 0.5 3 One 2 - TS100 ^{5 )} Matting agent 2.5 2.5 2.5 2.5 2.5 PnB ^{6 )} Paint film formation 15 15 15 15 15 BYK028 ^{7 )} Antifoam 0.5 0.5 0.5 0.5 0.5 Tinuvin292 ^{8 )} Light stabilizer 0.5 0.5 0.5 0.5 0.5 HV30 ^{9 )} Thickener 1.8 1.8 1.8 1.8 1.8 Pigmentation Pigment 4 4 4 4 4

* Mixed solvent: Mixed solvent of propylene glycol alkyl ether and propylene glycol alkyl ether acetate

1) Dow Chemical

2) TEGO Products

3) Angus

4) GE OSI Products

5) Degussa Products

6) Dow Chemical Products

7) BYK Products

8) CIBA Products

9) CIBA Products

< Experimental Example >

Each of the resins thus obtained was injection molded with an injection molding machine of 130 tons of clamping force, and the specific gravity, tensile strength, flexural modulus, Izod impact strength, and chemical resistance were measured, and the results are shown in Table 2 below.

Here, specific gravity was measured by ASTM D-792 method, tensile strength was measured by ASTM D-638 method, flexural modulus was measured by ASTM D-790 method, and Izod impact strength was measured by ASTM D-256 method. The results of 20 round trip rub tests with gauze towels, IPA, hand cream, glass cleaner, coffee, and wax were observed and evaluated as excellent 5 <----> 1 defect.

division Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Specific gravity (g / ㎠) 1.08 1.07 1.11 1.10 1.07 The tensile strength
(kgf / cm2) 375 360 362 353 285 Flexural modulus
(kgf / cm2) 21,500 19,600 18,900 19,100 17,100 Izod impact strength
(kgf · cm / cm) 3.5 3.3 3.2 3.3 2.3 Chemical resistance 5 4.5 5 4.5 2

As can be seen in Table 2, the coating composition according to the present invention was applied to a polyolefin-based automotive interior plastic material and measured for chemical resistance, which is a chemical property thereof, as compared with Comparative Example 1 without containing silane. It was confirmed that a coating composition having excellent chemical resistance could be obtained.

As described above, the resin composition according to the present invention further increases the crosslinking degree of the styrene-acrylic resin containing the polyolefin resin and the epoxy crosslinking agent by using a silane. Discoloration and peeling of the coating film which may occur due to the penetration of the chemical can be minimized, and thus it can be usefully used as a coating material for interior materials of automobiles.

Claims (7)

30 to 50 wt% chlorinated polyolefin water-soluble emulsion resin; Acrylic styrene-based copolymer water-soluble emulsion resin containing two epoxy-based epoxy crosslinking agents 10 to 20% by weight of propylene glycol solvents; 25-35 weight percent of ion-exchanged water; And water-soluble one-component coating composition for water-soluble polyolefin-based plastics excellent in chemical resistance comprising 0.1 to 3% by weight of silane. The water-soluble one-component coating composition for water-soluble polyolefin-based plastics having excellent chemical resistance according to claim 1, wherein the chlorinated polyolefin emulsion resin is chlorinated polypropylene having a chlorination degree of 10 to 70%, or polyethylene resin. The styrene-acrylic copolymer emulsion resin containing the epoxy-based crosslinking agent having two epoxy groups is copolymerized with styrene and an acrylic monomer to have a glass transition temperature in the range of 25 to 75 ° C. and a solid content of 20 to 50. A water-soluble, one-component coating composition for water-soluble polyolefin-based plastics having excellent chemical resistance, which is prepared to be by weight%. The method according to claim 3, wherein the styrene is styrene, or a derivative thereof, and the acrylic component is one or more selected from the group consisting of acrylic acid, methacrylic acid, methylmethacrylic acid, and acrylonitrile. Water-soluble one-component coating composition for water-soluble polyolefin-based plastics. The water-soluble water-soluble polyolefin-based plastic having excellent chemical resistance according to claim 1, wherein the propylene glycol solvent is selected from the group consisting of propylene glycol alkyl ether, propylene glycol alkyl ether acetate, and propylene glycol alkyl ether acetate. One component coating composition. The method of claim 1, wherein the silane is selected from the group consisting of vinylethoxysilane, vinylmethoxysilane, gamma methacryloxypropyltriethoxysilane, and gamma methacryloxypropyltrimethoxysilane. Water-soluble one-component coating composition for water-soluble polyolefin-based plastics excellent in chemical properties. According to claim 1, It may contain an additive, the additive is 0.1 to 0.5 parts by weight of wetting agent, 0.1 to 0.5 parts by weight of pH adjusting agent, 2-3 parts by weight of silica-based matting agent, based on 100 parts by weight of the total coating composition, 10 to 20 parts by weight of the coating film forming agent, 0.1 to 1 part by weight of antifoaming agent, 0.1 to 1 part by weight of light stabilizer, 1 to 2 parts by weight of medium and 1 to 10 parts by weight of coloring pigment, A water-soluble one-component coating composition for water-soluble polyolefin-based plastics excellent in chemical resistance.