JP2000007979A - Coating resin composition for polyolefin and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating resin composition improved in adhesion to a polyolefin resin molding and compatibility with a pigment-dispersed resin by grafting a hydroxyl-containing radically polymerizable unsaturated compound onto a specified acid-modified chlorinated polyolefin resin. SOLUTION: A polyolefin resin and 1-10 wt.% α,β-unsaturated carboxylic acid (anhydride) are reacted with each other in the presence of a radical generator by melting by heating to the melting point of the polyolefin resin or higher, and chlorine is introduced into the reaction mixture to obtain an acid-modified chlorinated polyolefin resin having a chlorine content of 12-28 wt.%, a content of grafted α,β-unsaturated carboxylic acid (anhydride) of 1-10 wt.% a weight- average molecular weight of 10,000-100,000, and a softening temperature of 60-120 deg.C 1-30 wt.% Hydroxyl-containing radically polymerizable unsaturated compound is grafted onto 99-70 wt.% obtained resin in the presence of a radical generator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a primer resin and a base coat resin used for painting a polyolefin molding, and a polyolefin having excellent adhesion to a polyolefin material and excellent compatibility with a pigment dispersion resin. The present invention relates to a coating resin composition for use.

[0002]

2. Description of the Related Art Plastics are widely used in recent years as materials for automobile parts, electric parts, building materials and the like because they have many advantages such as light weight, rust prevention and wide design flexibility. In particular, polyolefin-based resins are widely used as industrial materials because they have many excellent properties such as low price, moldability, chemical resistance, heat resistance, water resistance, and good electrical properties. Growth is also expected. However, unlike synthetic resins having polarity, polyolefin resins have non-polarity and crystallinity, and thus have the drawback of difficulty in painting and bonding.

[0003] As a pretreatment before coating or bonding, a method of activating the surface of a molded product by plasma treatment or gas flame treatment, or a chlorinated polyolefin obtained by graft copolymerizing an unsaturated carboxylic acid or the like (acid-modified chlorine) (A polyolefin) is applied by a two-coat method or the like.

On the other hand, compositions for one coat and base coat have been proposed for the purpose of omitting the step of primer coating. For example, Japanese Patent Publication No. 6-180801, International Publication Number WO
It is a coating composition containing a modified chlorinated polyolefin as a main component, which is found in 96/04344 and the like. Although these coating compositions easily adhere to conventional polyolefin materials, recently, as the rigidity of the materials has increased, the number of difficult-to-adhere materials has increased, and the modified chlorinated polyolefins have been increased. At present, a strong adhesive force is not obtained.

When the above-mentioned primer, that is, the unsaturated carboxylic acid-modified chlorinated polyolefin is used as a resin for one-coat or base-coat, it alone has weather resistance,
Because of poor physical properties such as moisture resistance and gloss, it is necessary to use a resin such as an acrylic resin, a polyester resin, and an alkyd resin, which is generally called a pigment dispersion resin. However, since the compatibility with these resins is inferior, not only the above-mentioned physical properties cannot be obtained, but also the adhesion is impaired.

The present inventors previously proposed in Japanese Patent Application No. 9-64227 a resin composition in which the softening temperature and average molecular weight of chlorinated polyolefin were optimized as an adhesive for polyolefin sheets. In order to satisfy physical properties as an adhesive, this resin composition is obtained by optimizing the softening temperature and average molecular weight of the acid-modified chlorinated polyolefin. Therefore, the compatibility with the pigment dispersion resin, which is the above problem, is insufficient. There was a difficulty in using it for paints such as base coats and one coats.

[0007]

DISCLOSURE OF THE INVENTION The present invention has excellent adhesion to thermoplastic polyolefin resin moldings such as polypropylene and polyethylene, which are difficult to adhere, and has a resin phase such as a pigment dispersion resin. An object of the present invention is to provide a coating resin composition for polyolefin having excellent solubility.

[0008]

Means for Solving the Problems The present inventors have found that the chlorine content is 12 to 28% by weight, and the graft amount of α, β-unsaturated carboxylic acid or its anhydride is 1 to 10% by weight, And a resin obtained by graft copolymerizing a hydroxyl group-containing radically polymerizable unsaturated compound with an acid-modified chlorinated polyolefin resin having a weight-average molecular weight of 10,000 to 100,000 has excellent compatibility with a pigment-dispersed resin, and is suitable for a polyolefin-based molded product. They have found that they show good adhesion and have solved the above problems.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The coating resin composition for polyolefin in the present invention has a chlorine content of 12 to 28% by weight,
the grafting amount of the α, β-unsaturated carboxylic acid or its anhydride is 1 to 10% by weight and the weight average molecular weight is 1000
0 to 100000 acid-modified chlorinated polyolefin resin,
It is made of a resin obtained by graft copolymerizing a hydroxyl group-containing radically polymerizable unsaturated compound.

The acid-modified chlorinated polyolefin is a component that adheres to the polyolefin resin. As a raw material of the acid-modified chlorinated polyolefin, isotactic polypropylene, syndiotactic polypropylene, atactic polypropylene, propylene-α-olefin copolymer, or the like can be used alone or in combination of two or more.

The α-olefin component used in the propylene-α-olefin copolymer is, for example, ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 3-methyl-1
-At least one selected from pentene and 1-hexene, an α-olefin having 2 or 4 to 6 carbon atoms is preferred, and the ratio of the propylene component to the α-olefin component in the copolymer is not particularly limited, Propylene component is 50
Desirably, it is at least mol%.

The coating resin composition for polyolefin of the present invention can be obtained by introducing an α, β-unsaturated carboxylic acid or its anhydride and chlorine into the above-mentioned polyolefin resin, and its production is carried out by the following two methods. Manufacturable. That is, a method in which an α, β-unsaturated carboxylic acid or an anhydride thereof is graft-polymerized to a polyolefin resin in advance and then a chlorination reaction is performed (first method).
This is a method (second method) in which an α, β-unsaturated carboxylic acid or its anhydride is graft-polymerized after the chlorination reaction is performed.

Hereinafter, a specific manufacturing method will be described.
In the first method, first, α, β
-The method of graft copolymerizing an unsaturated carboxylic acid or its anhydride is a method in which the above resin is heated and melted to a melting point or higher in the presence of a radical generator (melting method), or the above resin is dissolved in an organic solvent. After dissolving, a method of reacting by heating and stirring in the presence of a radical generator (solution method)
And other known methods.

In the case of the melting method, a Banbury mixer,
Since the reaction is carried out in a short time at a temperature of not less than the melting point and not more than 300 ° C. using a kneader, an extruder or the like, there is an advantage that the operation is simple.

On the other hand, in the solution method, it is desirable to use an aromatic solvent such as toluene or xylene as a solvent, but it is also possible to use a mixture of an ester solvent, a ketone solvent or the like. No problem. The radical generator used for the reaction can be appropriately selected from known ones,
Particularly, an organic peroxide compound is desirable.

Examples of the above-mentioned organic peroxide compounds include di-t-butyl peroxide, dicumyl peroxide, t-butyl cumyl peroxide, benzoyl peroxide, dilauryl peroxide, cumene hydroperoxide and t-butyl peroxide. -Butyl hydroperoxide,
1,1-bis (t-butylperoxy) -3,5,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) -cyclohexane, cyclohexanone peroxide, t-butylperoxybenzoate, t- Butyl peroxyisobutyle
-Tert-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisopropyl carbonate, cumylperoxyoctoate, etc. .

However, in the case of the solution method, a chlorination reaction is carried out after graft copolymerization of an α, β-unsaturated carboxylic acid or its anhydride, but it is necessary to replace the above solvent with a chlorinated solvent such as chloroform. Because
In order to graft copolymerize an α, β-unsaturated carboxylic acid or its anhydride onto a polyolefin resin in the first method, a melting method is preferred.

The subsequent chlorination reaction is carried out by dissolving a polyolefin resin obtained by graft copolymerizing an α, β-unsaturated carboxylic acid or its anhydride in a chlorine-based solvent such as chloroform, and then irradiating it with ultraviolet rays, or It is carried out by blowing gaseous chlorine in the presence of the above-mentioned organic peroxide.

In the second method, in which the chlorination reaction is carried out and then the α, β-unsaturated carboxylic acid or its anhydride is graft-polymerized, the polyolefin resin is dissolved in a chlorinated solvent such as chloroform, and After producing a chlorinated polyolefin resin by performing a chlorination reaction in the same manner as in the above method, the solvent is changed to a solvent such as toluene or xylene, and then α,
It is obtained by graft copolymerization of a β-unsaturated carboxylic acid or its anhydride in the presence of the above-mentioned organic peroxide. The reaction can be carried out at a temperature of not lower than 50 ° C. and not higher than the boiling point of the solvent.

In the first method and the second method, crystalline polypropylene, amorphous polypropylene, propylene
-α, β graft copolymerized to α-olefin copolymer
-Unsaturated carboxylic acid or anhydride thereof is for imparting adhesion to a top coat when the resin composition of the present invention is used as a primer paint or a base coat paint, for example, maleic acid, citraconic acid , Itaconic acid, aconitic acid and their anhydrides, acrylic acid, methacrylic acid, fumaric acid, mesaconic acid, etc., and maleic anhydride is most suitable in consideration of the graftability to polyolefin resins.

In the present invention, the amount of the α, β-unsaturated carboxylic acid or its anhydride to be introduced by graft copolymerization is optimally from 1 to 10% by weight. When the amount is less than 1% by weight, sufficient adhesion to the top coat is not obtained, and when it is 10% by weight or more, the moisture resistance tends to decrease.

The chlorine content of the acid-modified chlorinated polyolefin resin is an important factor that affects the adhesion to the polyolefin resin, and the lower the chlorine content, the better the adhesion to the polypropylene resin, and the higher the chlorine content, the higher the chlorine content. Adhesion with polypropylene resin is reduced. On the other hand, if the chlorine content is low, the solubility in an organic solvent is reduced. If the chlorine content is too low, it does not dissolve in the solvent. Most of the conventional chlorinated polypropylene was developed for paints and inks,
Chlorine content is typically 30% by weight to increase solvent solubility
That's all.

In the case of a molded article of a polyolefin such as polypropylene, a high adhesion strength is required, but simply reducing the chlorine content does not provide sufficient solvent solubility as described above. The inventors of the present invention disclosed in Japanese Patent Application No. 9-64227 that, by using a raw material polyolefin having a softening temperature of 110 to 180 ° C., the chlorine content was increased to 12 to 28% by weight, preferably 15 to 25% by weight. Although a chlorinated polyolefin that has excellent solvent solubility even when lowered is proposed, it is most suitable as the acid-modified chlorinated polyolefin used in the present invention.

In this case, if the chlorine content is less than 12% by weight, there is a disadvantage that the solvent solubility is inferior and the workability is reduced. If the chlorine content is more than 28% by weight, the adhesion to the polyolefin material is reduced. is there.

The resulting acid-modified chlorinated polyolefin resin was subjected to gel permeation chromatography (GP
It is preferable that the weight average molecular weight measured by C) using polystyrene resin as a standard is 10,000 to 100,000. If it is less than 10,000, the cohesive force of the coating is insufficient, and if it is more than 100,000, the viscosity becomes high, and it is difficult to spray-coat the polyolefin material, which is not preferable.

The softening temperature of the acid-modified chlorinated polyolefin resin is preferably set to 60 to 120 ° C. by appropriately selecting a chlorine content of 12 to 28% by weight. If the softening temperature is lower than 60 ° C, the wettability to the surface of the film or molded product is good, but there is a drawback that the cohesiveness of the coating material is reduced, and if it exceeds 120 ° C, the wettability to the film or molded surface is poor. Therefore, the adhesiveness decreases. In recent years, the baking temperature of the paint is often set at about 80 to 100 ° C., so the softening temperature is more preferably 70 to 100 ° C.

In addition, chlorinated resins are conventionally used by adding an epoxy compound as a stabilizer. The epoxy compound is not particularly limited, but is preferably compatible with the chlorinated resin, and has an epoxy equivalent of about 100 to 500.
An epoxy compound having one or more epoxy groups in one molecule can be exemplified.

For example, epoxidized soybean oil and epoxidized linseed oil obtained by epoxidizing a natural vegetable oil having an unsaturated group with a peracid such as peracetic acid. Epoxidized fatty acid esters obtained by epoxidizing unsaturated fatty acids such as oleic acid, tall oil fatty acid and soybean oil fatty acid. Epoxidized alicyclic compounds represented by epoxidized tetrahydrophthalate. Bisphenol A or polyhydric alcohol condensed with epichlorohydrin, for example, bisphenol A glycidyl ether,
Examples thereof include ethylene glycol glycidyl ether, propylene glycol glycidyl ether, glycerol polyglycidyl ether, and sorbitol polyglycidyl ether. Also, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, decyl glycidyl ether, stearyl glycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, sec-butyl phenyl glycidyl ether, tert-butyl phenyl glycidyl ether, phenol polyethylene oxide glycidyl ether, etc. Monoepoxy compounds are exemplified. In addition, calcium stearate used as a stabilizer for polyvinyl chloride resin, metal soaps such as lead stearate, organic metal compounds such as dibutyltin dilaurate and dibutylmalate, and hydrotalcite compounds can also be used. May be used in combination.

The acid-modified chlorinated polyolefin obtained as described above is usually made into a solution such as toluene and then subjected to a graft reaction by the method described below. A toluene solution of an acid-modified chlorinated polyolefin can be prepared by converting a chlorinated solvent such as chloroform as a reaction solvent into toluene by utilizing a difference in boiling points. Also, after adding an epoxy compound or the like as a stabilizer to a polyolefin resin dissolved in a reaction solvent such as chloroform, the mixture is supplied to an extruder equipped with a vent provided with a suction part for solvent removal on a screw shaft part, and solidified to form toluene. May be dissolved. The method of solidification uses a known method already known, for example, an extruder with a vent equipped with a submerged cut pelletizer at the outlet of the extruder, an extruder with a vent, a pelletizer for cutting a strand-like resin, and the like. Can be implemented.

The present invention is attained by graft copolymerizing the above-mentioned acid-modified chlorinated polyolefin with a hydroxyl group-containing radically polymerizable unsaturated compound. The optimal ratio is between 99: 1 and 70:30. Outside this range, the adhesion to the polyolefin-based material is reduced, or the compatibility with other resins is reduced, which is not preferable.

The most suitable method for graft copolymerization of an acid-modified chlorinated polyolefin resin and a hydroxyl group-containing radically polymerizable unsaturated compound is solution polymerization. As the solvent used for the reaction, an aromatic solvent such as toluene and xylene, an alicyclic solvent such as cyclohexane, methylcyclohexane, and ethylcyclohexane can be mainly used, but an ester solvent such as ethyl acetate, butyl acetate, methyl ethyl ketone, and methyl isobutyl ketone can be used. Ketone solvents can also be used. In addition, an alcohol-based solvent such as isopropyl alcohol can be partially added and used.

A specific method of copolymerization is to heat the acid-modified chlorinated polyolefin resin dissolved in the above-mentioned solvent, and to react while gradually adding a radical generator and a radical polymerizable unsaturated material to the basic process. However, these may be mixed in advance, a radical generator may be added, and then the mixture may be heated and reacted.

Examples of the hydroxyl group-containing radically polymerizable unsaturated compound include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate,
Hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, (4-hydroxymethylcyclohexyl) -methyl acrylate, (4-hydroxymethylcyclohexyl) -methyl methacrylate, 2-acryloyloxyethyl- 2-hydroxypropyl phthale
And polycaprolactone-modified acrylate and polycaprolactone-modified methacrylate obtained by esterifying 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate with caprolactones.

Further, any compound having a hydroxyl group and a radical polymerizable double bond in the molecule, such as carbonate-modified methacrylates having a primary hydroxyl group and a radical polymerizable double bond in the molecule, can be used. is there.

As the radical generator, azo compounds, nitroso compounds, redox compounds and the like can be used in addition to the above-mentioned organic peroxides.

The resin composition obtained by graft copolymerizing the acid-modified chlorinated polyolefin according to the present invention with a hydroxyl-containing radically polymerizable unsaturated compound may be used as it is, but the resin composition of the present invention is not compatible with other resins. Is improved, a resin called a pigment dispersion resin such as an acrylic resin, a urethane resin, a polyester resin, and an alkyd resin may be used in combination. In addition, inorganic pigments such as aluminum paste, aluminum oxide, titanium dioxide, talc, calcium carbonate, and other organic pigments, antioxidants, ultraviolet absorbers, light stabilizers, antiblocking agents, and other additives are used. You may.

[0037]

The present invention is characterized in that a hydroxyl-containing radical polymerizable unsaturated compound is graft-copolymerized to an acid-modified chlorinated polyolefin resin to obtain a pigment-dispersed resin such as an acrylic resin, an alkyd resin, or a polyester resin. Is improved, whereby the weather resistance, moisture resistance, gloss and the like of the paint can be improved. In addition, by improving the compatibility thereof, the adhesion to polyolefin-based molded products is remarkably superior to the modified chlorinated polyolefins disclosed in Japanese Patent Publication No. 6-180801 and International Publication No.WO96 / 04344. The point is that a resin composition for paint can be obtained.

The acid-modified chlorinated polyolefin has a small amount of polarity due to the introduction of carboxylic acid and chlorine, but has poor compatibility with pigment-dispersed resins such as alkyd resins. However, it has been found that compatibility with a pigment-dispersed resin is improved by graft copolymerizing a radical polymerizable unsaturated compound having a hydroxyl group. This is probably because the introduction of a highly polar hydroxyl group improved the polarity of the acid-modified chlorinated polyolefin.

Further, even in a paint using these pigment-dispersed resins in combination, the more uniformly compatible, the better the adhesion to the material. Although the cause is not clear, when the compatibility between the acid-modified chlorinated polyolefin and the pigment dispersing resin is poor, they cause phase separation in the coating film, and the acid-modified chlorinated polyolefin as an adhering component is added to the material. It is thought that it was blocking access.

[0040]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited thereto.

[Trial Production Example 1] In a four-necked flask equipped with a stirrer, a cooling tube, a thermometer and a dropping funnel, 500 g of isotactic polypropylene was heated and dissolved at 200 ° C. After purging with nitrogen in the flask for 10 minutes, 25 g of maleic anhydride was added thereto with stirring over about 5 minutes, and 2 g of di-t-butyl peroxide as a radical generator was added dropwise over about 30 minutes. After the reaction was further continued for 30 minutes, unreacted maleic anhydride was removed while reducing the pressure in the flask with an aspirator. The grafted amount of maleic anhydride of this product was 4.4% by weight. Next, this product is charged into a glass-lined reaction vessel, 5 L of chloroform is added, and gaseous chlorine is radiated under ultraviolet light under a pressure of ² kg / cm ² until the chlorine content becomes 22.2% by weight. It was blown from the bottom of the reactor. After completion of the reaction, 24 g of Epikote 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) was added as a stabilizer, and chloroform, which was a solvent, was distilled off with an evaporator. A 20% solution of chlorinated polyolefin modified with maleic acid was obtained. The resin had a weight average molecular weight of 56000 and a softening temperature of 86 ° C. Table 1 shows the properties.

[Trial Production Example 2] Graft copolymerization of maleic anhydride (20 g) was carried out in the same manner as in Trial Production Example 1 to 500 g of isotactic polypropylene. The grafted amount of maleic anhydride of this product was 3.5% by weight. Furthermore, a 20% solution of a chlorinated polyolefin modified with maleic anhydride and chlorinated to a chlorine content of 20.6% by weight in the same manner as in Prototype Example 1 (solvent composition: toluene / cyclohexane = 50/50 (weight ratio))
I got This resin had a weight average molecular weight of 94000 and a softening temperature of 90 ° C.

[Trial Production Example 3] 33 g of maleic anhydride was graft-copolymerized to 500 g of an ethylene-propylene copolymer having an ethylene content of 6.1 mol% in the same manner as in Production Example 1. The grafted amount of maleic anhydride in this product was 5.5% by weight. In addition, the chlorine content was 18.2 by the same operation as in Prototype Example 1.
A 20% solution of chlorinated polyolefin modified with maleic anhydride (solvent composition: toluene / cyclohexane = 75/25 (weight ratio)) was obtained by chlorinating to weight%. The resin had a weight average molecular weight of 60,000 and a softening temperature of 72 ° C.

[Trial Production Example 4] 30 g of maleic anhydride was graft-copolymerized to 500 g of isotactic polypropylene in the same manner as in Production Example 1. The grafted amount of maleic anhydride in this product was 5.0% by weight. Next, this product is charged into a glass-lined reaction vessel, 5 L of chloroform is added, and gaseous chlorine is added under a pressure of ² kg / cm ² while irradiating ultraviolet rays until the chlorine content becomes 24.6% by weight. It was blown from the bottom of the reactor. After the reaction is completed, Epiol SB is used as a stabilizer.
24 g (manufactured by NOF Corporation) was added, and the mixture was supplied to an extruder equipped with a vent provided with a suction part for solvent removal on the screw shaft part to remove the solvent and solidify. The obtained solid was dissolved in a mixed solvent having a solvent composition of toluene / cyclohexane = 50/50 (weight ratio) to obtain a chlorinated polyolefin modified with maleic anhydride having a solid content of 20%. The resin had a weight average molecular weight of 70,000 and a softening temperature of 71 ° C.

[Trial Production Example 5] In 500 g of isotactic polypropylene, 25 g of maleic anhydride was graft-copolymerized in the same manner as in Trial Production Example 1. The grafted amount of maleic anhydride of this product was 4.5% by weight. Furthermore, a 20% solution of a chlorinated polyolefin modified with maleic anhydride and chlorinated to a chlorine content of 19.2% by weight in the same manner as in Prototype Example 1 (solvent composition: toluene / cyclohexane = 50/50 (weight ratio))
I got The weight average molecular weight of this resin was 20,000, and the softening temperature was 87 ° C.

[Trial Production Example 6] In 500 g of isotactic polypropylene, 20 g of maleic anhydride was graft-copolymerized in the same manner as in Trial Production Example 1. The grafted amount of maleic anhydride of this product was 3.5% by weight. Further, a 20% solution of a chlorinated polyolefin modified with maleic anhydride and chlorinated to a chlorine content of 31.2% by weight in the same manner as in Prototype Example 1 (solvent composition: toluene / cyclohexane = 90/10 (weight ratio))
I got This resin had a weight average molecular weight of 65,000 and a softening temperature of 64 ° C.

[Trial Production Example 7] 20 g of maleic anhydride was graft-copolymerized to 500 g of an ethylene-propylene copolymer having an ethylene content of 3.2 mol% in the same manner as in Trial Production Example 1. The grafted amount of maleic anhydride of this product was 3.5% by weight. Further, a chlorination reaction was carried out by the same operation as in Prototype Example 1, and a 20% solution of maleic anhydride-modified chlorinated polyolefin having a chlorine content of 19.1% by weight (solvent composition: toluene / cyclohexane = 50/50 (weight ratio)). Obtained. The resin had a weight average molecular weight of 70,000 and a softening temperature of 110 ° C.

Example 1 950 g of the resin solution (solid content: 20%) obtained in Prototype Example 1 was placed in a four-necked flask equipped with a stirrer, a condenser, a thermometer, and a dropping funnel. The mixture was purged with nitrogen and heated to 90 ° C. while stirring to maintain the temperature. Next, after adding 3 g of benzoyl peroxide, 10 g of 2-hydroxyethyl acrylate was added from a dropping funnel over 60 minutes, and the reaction was further continued for 3 hours. The concentration was adjusted to 20 wt% with toluene to obtain an acid-modified chlorinated polyolefin grafted with radically polymerizable unsaturated substances.

Examples 2 to 8 and Comparative Examples 1 to 4 The same as in Example 1 except that the maleic acid-modified chlorinated polyolefin and the radically polymerizable unsaturated compound used for the modification were changed to the amounts and substances shown in Table 2. A trial production was conducted by a simple operation to obtain an acid-modified chlorinated polyolefin grafted with a radical polymerizable unsaturated substance.

Comparative Example 5 Isotactic polypropylene was placed in a four-necked flask equipped with a stirrer, condenser, thermometer and dropping funnel.
500g was heated and dissolved at 200 ° C. After purging with nitrogen in the flask for 10 minutes, 20 g of maleic anhydride was added thereto over about 5 minutes while stirring, and 2 g of di-t-butyl peroxide as a radical generator was added dropwise over about 30 minutes. Plus 30
After the reaction was continued for minutes, unreacted maleic anhydride was removed while reducing the pressure in the flask with an aspirator. The grafted amount of maleic anhydride of this product was 3.5% by weight. Next, this product is put into a glass-lined reaction vessel, 5 L of chloroform is added, and gaseous chlorine is added under a pressure of ² kg / cm ² while irradiating ultraviolet rays until the chlorine content becomes 24.5% by weight. It was blown from the bottom of the reactor. After completion of the reaction, 24 g of Epikote 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) was added as a stabilizer, and chloroform as a solvent was distilled off with an evaporator, and the chlorinated polyolefin modified with maleic anhydride and substituted with toluene was replaced with toluene. 20% solution (1)
I got The weight average molecular weight of this resin was 56,000.

On the other hand, isotactic polypropylene 50
0 g was charged into a glass-lined reaction vessel, 5 L of chloroform was added, and gaseous chlorine was blown from the bottom of the reaction vessel while irradiating ultraviolet rays under a pressure of ² kg / cm ² to perform a chlorination reaction. When the chlorine content reached about 20% by weight, the chlorination reaction was continued while performing the oxidation treatment by replacing the chlorine gas with a mixed gas of chlorine / oxygen. When the chlorine content reached 30.5% by weight, the chlorination reaction was terminated, and Epicoat 82 was used as a stabilizer.
8 (manufactured by Yuka Shell Epoxy Co., Ltd.) was added, and chloroform, which was a solvent, was distilled off by an evaporator, and the solvent was replaced with toluene, and a 50% solution of an oxidized chlorinated polyolefin (2) was added.
I got The weight average molecular weight of this resin was 11,000.

Next, a 20% solution of the obtained maleic anhydride-modified chlorinated polyolefin was placed in a four-necked flask equipped with a stirrer, a condenser, a thermometer and a dropping funnel.
(1) 375 g, 50% solution of oxidized chlorinated polyolefin
(2) 50 g and 175 g of toluene were added, the atmosphere in the flask was replaced with nitrogen, and the mixture was heated to 90 ° C. while stirring to maintain the temperature.
Next, 5 g of benzoyl peroxide was added, 137 g of methyl methacrylate, 205 g of lauryl methacrylate, and 58 g of 2-hydroxyethyl acrylate were added from a dropping funnel over 3 hours, and the reaction was further continued for 7 hours to obtain a uniform and transparent resin solution ( (Solid content: 50 wt%).

Compatibility test An acrylic resin (Mw (weight average molecular weight) = 19,000, OHV (hydroxyl value) = 56 KOH mg / g) or an alkyd was added to the resin solutions obtained in Examples 1 to 8 and Comparative Examples 1 to 5. Resin (Mw = 38000
, OHV = 70KOHmg / g) or an oil-free polyester resin (Mw = 51000, OHV = 56KOHmg / g) was mixed so that the weight ratio would be 1/1, and the mixed solution when the solid content was adjusted to 20% Was evaluated. Table 3 shows the results.

Paint test-1 A resin solution (solid content: 20%) shown in Table 4 in which the weight ratio of the resin obtained in Examples 1 to 8 and Comparative Examples 1 to 5 to the pigment-dispersed resin was 1/1. Add and mix 3g of aluminum paste to 100g,
The viscosity was adjusted with xylene at 13 to 15 seconds / 20 ° C with a NO.4 Ford cup, and the ultra-high rigidity polypropylene plate washed with IPA was painted with an air spray gun.
Next, a two-component curable urethane paint (clear) was applied. It was dried at 80 ° C. for 30 minutes and left at room temperature for 24 hours to evaluate its physical properties. Table 4 shows the results of the coating film test. The evaluation test is as follows.

● Adhesion A grid of 100 pieces was formed on the coated surface to reach the substrate at 1 mm intervals, and a cellophane adhesive tape was adhered thereon and peeled off in a 180 ° direction, and the degree of the remaining coating film was determined. . ● Gasoline resistance Painted plate made regular gasoline / ethanol = 9/1 (v / v)
After immersion for 120 minutes, the state of the coating film was observed. ● Moisture resistance The coated plate was immersed in warm water of 40 ° C for 240 hours, and the condition and adhesion of the coating film were examined. ● Appearance of coating film The appearance of the coating film after drying was observed.

Paint test-2 A resin solution (solid content: 20%) shown in Table 5 in which the weight ratio of the resins obtained in Examples 1 to 8 and Comparative Examples 1 to 4 to the pigment-dispersed resin was 1/1. 13 g of titanium dioxide is added to 100 g or 40 g of the resin solution of Comparative Example 5 (solid content: 50%), and the mixture is kneaded with a sand mill for 2 hours. Then, an isocyanate curing agent desmophen N-3500 (manufactured by Sumitomo Bayer Urethane Co., Ltd.) is added. NCO / OH =
Add 1.0 (molar ratio), adjust viscosity with xylene to 13 ~ 15sec / 20 ℃ with NO.4 Ford cup, and pneumatic spray gun on ultra-high rigidity polypropylene plate washed with IPA Painted by. It was dried at 80 ° C. for 30 minutes and left at room temperature for 24 hours to evaluate its physical properties. Table 5 shows the results of the coating film test. The evaluation test is as follows.

● Adhesion A grid of 100 pieces was formed on the coated surface to reach the substrate at 1 mm intervals, and a cellophane adhesive tape was adhered thereon and peeled off in a 180 ° direction, and the degree of the remaining coating film was determined. . ● Oil resistance Butter was dropped on the painted surface, and the state of the coating film when rubbed with absorbent cotton was observed. ● Moisture resistance The coated plate was immersed in warm water of 40 ° C for 240 hours, and the condition and adhesion of the coating film were examined. ● Appearance of coating film The appearance of the coating film after drying was observed.

[0058]

[Table 1]

[0059]

[Table 2]

[0060]

[Table 3]

[0061]

[Table 4]

[0062]

[Table 5]

[0063]

From the above test results, it can be seen that the compatibility with a pigment-dispersed resin such as a polyester resin, an acrylic resin, and a polyester resin is improved by graft copolymerizing a hydroxyl-containing radically polymerizable unsaturated compound. I understand.
In addition, it can be seen that paint properties such as adhesion and appearance of the coating film are also improved. In the case of a chlorinated polyolefin obtained by acrylic modification (resin of Comparative Example 5), a good coating film appearance can be obtained, but the adhesion is quite poor.

Continued on the front page (72) Inventor Keiji Urata 2-8-1 Iidacho, Iwakuni-shi, Yamaguchi Prefecture Nippon Paper Industries Co., Ltd. Chemical Development Laboratory F-term (reference) 4J038 CB171 CP051 GA03 GA06 GA06 GA12 NA02 NA12 PC08

Claims (5)

[Claims] 1. A chlorine content of 12 to 28% by weight, a grafting amount of an α, β-unsaturated carboxylic acid or an anhydride thereof of 1 to 10% by weight, and a weight average molecular weight of 10,000 to 100,000. A coating resin composition for polyolefin, comprising graft-copolymerizing an acid-modified chlorinated polyolefin resin with a hydroxyl-containing radically polymerizable unsaturated compound. 2. The weight ratio of the acid-modified chlorinated polyolefin resin to the hydroxyl-containing radically polymerizable unsaturated compound is from 99: 1 to 7
The coating resin composition for polyolefin according to claim 1, wherein the ratio is 0:30. 3. The coating resin composition for a polyolefin according to claim 1, wherein the softening temperature of the acid-modified chlorinated polyolefin resin is from 60 to 120 ° C. 4. The method according to claim 1, wherein the acid-modified chlorinated polyolefin resin is polypropylene or propylene and C 2 or C 4.
The coating resin composition for a polyolefin according to any one of claims 1 to 3, wherein the resin is a resin obtained by copolymerizing α-olefins (1) to (6). 5. An acid-modified chlorination in which an α, β-unsaturated carboxylic acid or its anhydride is graft copolymerized with a raw polyolefin in an amount of 1 to 10% by weight, and then chlorinated to a chlorine content of 12 to 28% by weight. A method for producing a coating resin composition for polyolefin, comprising graft-copolymerizing a hydroxyl group-containing radically polymerizable unsaturated compound to a polyolefin resin.