JPH1030040A - Chlorinated polypropylene-containing resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition excellent in storage stability and capable of giving coatings excellent weatherability by compounding a chlorinated polypropylene-modified acrylic resin with an antioxidizing agent. SOLUTION: This chlorinated polypropylene-containing resin composition comprises (A) a chlorinated polypropylene-modified acrylic resin comprising (i) a chlorinated polypropylene and (ii) one or more kinds of a (meth)acrylate ester, a hydroxyl group-containing (meth)acrylate ester and an α, '-unsaturated carboxylic acid and (B) an antioxidizing agent (e.g. p-methoxtyphenol). The component B is preferably compounded in an amount of 50-10000ppm based on the component A, and the components (i) and (ii) are preferably compounded in a ratio 5/95 to 40/60. (C) A radical-catching agent is preferably further compounded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for a paint suitable for coating a molded article of a polypropylene resin such as a bumper of an automobile or a household electric appliance.

[0002]

2. Description of the Related Art Conventionally, lightweight and excellent impact resistance polypropylene resin has been widely used for automobile bumpers, household electric appliances and the like. These molded products are often coated on the surface for the purpose of decoration and protection. In this case, a method of mixing an acrylic resin or the like with a chlorinated polyolefin or the like is known. For example, JP-A-58-
JP-A-71966, JP-B-51-24316, JP-B-2-3828 and the like disclose chlorinated polypropylene and (meth) as a resin for a paint for a polypropylene resin.
It is disclosed to use a chlorinated polypropylene-modified acrylic resin comprising one or more monomer mixtures selected from acrylic acid esters, hydroxyl group-containing (meth) acrylic acid esters, and α, β-unsaturated carboxylic acids. ing.

However, these resins have poor storage stability and weather resistance, which are considered to be caused by the use of chlorinated polypropylene, and generate coarse particles during storage or gel the resin. There were considerable limitations in the field of application. Further, even if various restrictions were provided, a satisfactory result was not necessarily obtained. For this reason,
In order to avoid such disadvantages, various studies have been made on paints for polypropylene, but none of them have been satisfactory yet.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems.
The purpose of the present invention is to improve the storage stability of a chlorinated polypropylene-modified acrylic resin and to improve the weather resistance of a paint obtained from the resin.

[0005]

To achieve the above object, the present invention has the following arrangement. That is, a chlorinated polypropylene comprising a chlorinated polypropylene and one or more monomer mixtures selected from (meth) acrylate, hydroxyl-containing (meth) acrylate and α, β-unsaturated carboxylic acid. It is a chlorinated polypropylene-containing resin composition obtained by mixing an antioxidant with a polypropylene-modified acrylic resin.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The chlorinated polypropylene in the present invention is not particularly limited, and commercially available ones may be appropriately used. However, the stability of the chlorinated polypropylene itself and the adhesion to the polypropylene as a base material are considered. In terms of properties, those having a chlorine content of 20 to 40% and a molecular weight of 5000 to 100,000 are preferably used.

[0007] In the present invention, the (meth) acrylate means methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, acrylic acid 2
-Ethylhexyl, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate,
Isobutyl methacrylate, tertiary butyl methacrylate, cyclohexyl methacrylate, 2-methacrylic acid
Examples include ethylhexyl, lauryl methacrylate, stearyl methacrylate, isobornyl methacrylate, dicyclopentenyloxyethyl methacrylate, and the like. These monomers may be used alone or as a mixture of two or more.

In the present invention, the hydroxyl group-containing (meth) acrylate is defined as 2-hydroxyethyl acrylate,
2-hydroxypropyl acrylate, 2-methacrylic acid
Examples include hydroxyethyl, 2-hydroxypropyl methacrylate, caprolactone adduct of acrylic acid or methacrylic acid, and these monomers may be used alone or as a mixture of two or more.

Further, in the present invention, α, β-unsaturated carboxylic acid includes acrylic acid, methacrylic acid, maleic acid,
There are maleic anhydride, itaconic acid and the like, and these monomers may be used alone or as a mixture of two or more.

In the present invention, chlorinated polypropylene and one or more monomers selected from the above-mentioned (meth) acrylates, hydroxyl-containing (meth) acrylates, and α, β-unsaturated carboxylic acids are used. The weight ratio to the body mixture is preferably 5/95 to 40/60. Specifically, the monomer mixture is subjected to radical polymerization in the presence of chlorinated polypropylene in accordance with a conventional method described later, thereby obtaining a chlorinated polypropylene-modified acrylic resin. Can be prepared.

In the present invention, examples of the antioxidant include a phenolic antioxidant, a bisphenol-based antioxidant, a polymer-type phenol-based antioxidant, a phosphorus-based antioxidant, and a sulfur-based antioxidant. The inhibitors may be used alone or as a mixture of two or more. Among these, in particular, a phosphorus-based antioxidant alone, or a phosphorus-based antioxidant and a phenol-based antioxidant, a phosphorus-based antioxidant and a bisphenol-based antioxidant, a phosphorus-based antioxidant and a polymer-type phenol-based It is effective to mix and use an antioxidant, a combination of a phosphorus antioxidant and a sulfur antioxidant.

As phenolic antioxidants, 2,6
-Di-t-butyl-P-cresol, P-methoxyphenol, butylated hydroxyanisole, 2,6-di-
As t-butyl-4-ethylphenol and bisphenol-based antioxidants, 2,2′-methylene-bis- (4
-Methyl-6-t-butylphenol), 2,2'-methylene-bis- (4-ethyl-6-t-butylphenol), and tetrakis- [methylene-3- ( 3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, and as a phosphorus-based antioxidant, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite , Triphenyl phosphite, cyclic neopentanetetraylbis (octadecyl phosphite),
Examples of the sulfur-based antioxidant include dilauryl thiodipropionate, dimyristyl thiodipropionate, and the like. (Reference: Chemical product of 129996 (Chemical Industry Daily)) The antioxidant is preferably incorporated in the chlorinated polypropylene-modified acrylic resin in an amount of 50 ppm or more, more preferably 100 ppm or more and 100,000 ppm or less. In addition, it is also possible to mix various diluting solvents, ultraviolet absorbers and the like as needed. In particular, when 2,4-diphenyl-4-methyl-1-pentene, which is a radical promoter, is combined with an antioxidant, the storage stability is further improved.

In particular, when a hydroxyl group-containing (meth) acrylate is blended with the chlorinated polypropylene-containing resin composition of the present invention, when the composition is used in a curing type paint in which a polyisocyanate compound, a melamine resin or the like is blended as a curing agent, crosslinking occurs. Since a coating film is formed, chemical resistance, weather resistance, and the like of the coating film can be dramatically improved. At this time, when a polyisocyanate compound is used as a curing agent, the compound is used for the chlorinated polypropylene-containing resin composition of the present invention in that crosslinking is appropriately caused and a coating material having excellent adhesion and flexibility is obtained. When the equivalent ratio of NCO / OH is 0.5 to
It is preferable to use it so as to be 2.0. When a melamine resin is used as a curing agent, the chlorinated polypropylene-containing resin composition of the present invention is obtained in that crosslinking is appropriately caused, and a paint having excellent coating performance such as water resistance and chemical resistance of the paint is obtained. It is preferable to use 5 to 40% by weight of the resin. In particular, when coating on polypropylene, the baking temperature cannot be set too high, and in this regard, polyisocyanate compounds and blocked polyisocyanate compounds are more preferably used than melamine resins.

Next, an example of the method for producing the chlorinated polypropylene-containing resin composition of the present invention will be described. First, in the presence of chlorinated polypropylene, α,
Azo-based polymerization initiators such as α'-azobisisobutyronitrile, benzoyl peroxide, t-butyl-peroxy-2-
Using an organic peroxide such as ethylhexanoate, at a polymerization temperature of 50 to 120 ° C., an aromatic solvent such as toluene and xylene, an ethyl acetate, and an acetic ester solvent such as butyl acetate;
A ketone-based solvent such as methyl ethyl ketone or methyl isobutyl ketone is used as a polymerization solvent, and (meth) acrylate, hydroxyl-containing (meth) acrylate, α, β-
A chlorinated polypropylene-modified acrylic resin is produced by solution polymerization of one or more monomer mixtures selected from unsaturated carboxylic acids. Next, a predetermined amount of an antioxidant is added to the prepared chlorinated polypropylene-modified acrylic resin, and the mixture is stirred and mixed until the antioxidant is uniformly dissolved to obtain a chlorinated polypropylene-containing resin composition.

Hereinafter, the present invention will be described in more detail with reference to Examples. Each evaluation in the examples is measured and determined by the following method.

(1) Particle size Measured according to JIS K-5400 using a tub gauge. In the examples, the acceptance criterion of the particle size is 50 μm or less.

(2) State The flow state of the resin in the glass bottle is visually observed. At this time, no change was observed as compared to before the test, and the sample having good flowability and no gel-like particles was evaluated as ○. The sample with good flowability but gel-like particles was confirmed as △. Is set to x, and △ and △ are passed criteria.

(3) Alcohol resistance The coating film is rubbed 20 times with absorbent cotton impregnated with a solution of ethanol / water (1/1) to observe the deterioration of the coating film. At this time, when the coating film did not cause whitening or tearing and there was no abnormality, ○, when the coating film was slightly whitened but did not tear, Δ
If the coating film breaks, it is marked as x, and ○ and △ are passed.

(4) Gasoline resistance The coating film was rubbed 20 times with absorbent cotton impregnated with white gasoline,
Observe the deterioration of the coating. At this time, when the coating film did not cause whitening, softening, tearing, etc., and there was no abnormality, ○, when the coating film was slightly whitened / softened, △, when the coating film was broken, ×, ○, △ And

(5) Water resistance The coating film is immersed in warm water at 40 ° C. for 3 days, and the state of deterioration of the coating film is observed. At this time, the whitening of the coating film, no change in the appearance of blisters and the like and no change were observed. ○: The coating film was slightly whitened and small blisters were generated. △: The coating film was whitened and the blistering was generated by ×. And △ and △ are acceptable criteria.

(6) Weather resistance According to JIS K-5400, sunshine weather
The accelerated weather resistance test was performed at 0 meter for 1000 hours.
The higher the value of the gloss retention (%), the higher the color difference (ΔE)
The smaller the value, the better the weather resistance. Gloss retention 80
% And a color difference ΔE of 0.5 or less are regarded as acceptance criteria.

[0022]

【Example】

Example 1 A chlorinated polypropylene "Hardlen 14LLB" (manufactured by Toyo Kasei Co., Ltd., active ingredient 15) was placed in a 2 L four-necked flask equipped with a thermometer, a stirrer, a reflux condenser, and a monomer dropping device.
%, Chlorine content 27%) and 11 g of toluene were charged and the temperature was raised to 93 ° C. 139.6 g of methyl methacrylate and isobornyl methacrylate 4 were added to the monomer dropping device.
g, methacrylic acid 1.4 g, t-butyl peroxy-2
-Ethyl hexanoate (1.0 g) was charged and uniformly mixed, and then added dropwise to the flask over 3 hours.

After 60 minutes from the end of the dropwise addition of the monomer mixed solution, azobisisobutyronitrile 0.4 is added every 30 minutes.
g, 4 g of methyl isobutyl ketone are added four times. Thereafter, after the polymerization is continued for 1 hour, 38 g of methyl isobutyl ketone is charged and cooled to 50 ° C. to terminate the polymerization, thereby obtaining a chlorinated polypropylene-modified acrylic resin.

A chlorinated polypropylene-containing resin composition is produced by mixing 2% by weight of P-methoxyphenol, which is a phenolic antioxidant, with the obtained chlorinated polypropylene-modified acrylic resin. Next, volume 100m
30 ml of the obtained resin was placed in a 1 l colorless and transparent glass bottle, sealed, sealed and allowed to stand under the following conditions, and the particle size and condition of the resin were examined. Table 1 shows the results. Condition A: allowed to stand at room temperature for 30 days Condition B: allowed to stand at 5 ° C for 10 days Condition C: stored at -5 ° C for 4 hours and stored at 30 ° C for 4 hours
The sample is allowed to stand in a cooling / heating cycle tester, and the cycle is repeated for 7 cycles. As is clear from Table 1, under the conditions A and B, the particle size and state of the resin after storage were good, and sufficiently satisfactory results were obtained even under the severe condition C where the temperature change was remarkable.

Example 2 In addition to adding 2% by weight of P-methoxyphenol to a chlorinated polypropylene-modified acrylic resin, 2,4-
0.5% of diphenyl-4--4-methyl-1-pentene
A resin was obtained in the same manner as in Example 1 except that it was blended, and the resin was used and stored under the same conditions A to C as in Example 1. Table 1 shows the results. As is clear from Table 1, the particle size and state of the resin after storage were even better than the resin obtained in Example 1 under any of the conditions A to C.

Example 3 As an antioxidant to be blended, phosphorus-based antioxidant 2,
2-methylenebis (4,6-di-t-butylphenyl)
Except that 2% by weight of octyl phosphite was blended, the same resin as in Example 1 was used and stored under the same three conditions. Table 1 shows the results. As is clear from Table 1, the particle size and state of the resin after storage were very good under any of the conditions A to C.

Example 4 A chlorinated polypropylene "Hardlen 14LLB" (manufactured by Toyo Kasei Co., Ltd., active ingredient 15) was placed in a 2 L four-necked flask equipped with a thermometer, a stirrer, a reflux condenser, and a monomer dropping device.
%, Chlorine content 27%) and 11 g of toluene were charged and the temperature was raised to 93 ° C. 238.2 g of methyl methacrylate and isobornyl methacrylate 14 were added to the monomer dropping device.
g, 40 g of 2-hydroxyethyl methacrylate, 1.4 g of methacrylic acid, and 1.0 g of t-butylperoxy-2-ethylhexanoate, uniformly mixed, and then added dropwise to the flask over 3 hours. After 60 minutes from the completion of the dropping of the monomer mixed solution, a mixture of 0.4 g of azobisisobutyronitrile and 4 g of methyl isobutyl ketone is added four times every 30 minutes. Thereafter, after the polymerization is continued for 1 hour, 38 g of methyl isobutyl ketone is charged and cooled to 50 ° C. to terminate the polymerization, thereby obtaining a chlorinated polypropylene-modified acrylic resin.

The chlorinated polypropylene-modified acrylic resin thus obtained was added to the phosphorus-based antioxidant 2,2
-Methylene bis (4,6-di-t-butylphenyl) octyl phosphite is blended at 2% by weight to produce a chlorinated polypropylene-containing resin composition. Using the obtained resin, storage was performed under the same three conditions as in Example 1. Table 1 shows the results. As is clear from Table 1, the particle size and state of the resin after storage were very good under any of the conditions A to C.

Comparative Example 1 The same resin as in Example 1 was used, except that no antioxidant was added to the chlorinated polypropylene-modified acrylic resin, and stored under the same three conditions as in Example 1. Table 1 shows the results
Shown in As is clear from Table 1, even under the conditions A and B, the particle size of the resin after storage was large and gel particles were observed. Under the condition C, the entire resin gelled, and it was impossible to use the resin. .

[0030]

[Table 1] Example 5 The resin compositions of Example 3 and Comparative Example 1 were each subjected to toluene / butyl acetate / anone = 60/20/20 (% by weight).
, And the paint viscosity was adjusted with Ford Cup # 4 for 15 seconds according to JIS K-5400.

Each paint was applied to a polypropylene TSOP (manufactured by Mitsubishi Chemical Corporation) test panel whose painted surface was cleaned with isopropyl alcohol by air spray so that the coating thickness was 30 μm. Each coated plate was dried at 80 ° C. for 30 minutes, and further dried at room temperature for 7 days, and the weather resistance was examined. The gloss retention of the resin using the resin of Example 3 was 90%, and ΔE was 0.4. In contrast, the gloss retention of the paint using Comparative Example 1 was 60%.
% And ΔE were 0.8, which were not practically sufficient.

Example 6 Chlorinated polypropylene-containing resin composition 100 of Example 4
g to the polyisocyanate compound “Sumidur N-7”
5 "(manufactured by Sumitomo Bayer Urethane Co., Ltd.) 6.2 g (NC
O / OH = 0.8) and mix well until uniform.
Mix. This is toluene / butyl acetate / anone = 60
/ 20/20 (wt%) mixed solvent
According to K-5400, the paint viscosity was adjusted with Ford Cup # 4 so as to be 15 seconds. This paint is a polypropylene TS whose painted surface is cleaned with isopropyl alcohol.
An OP (manufactured by Mitsubishi Chemical) test panel was applied by air spray so as to have a coating thickness of 30 μm. After baking and drying the coated plate at 80 ° C. for 30 minutes,
Dry for days, alcohol resistance, gasoline resistance, water resistance,
The weather resistance was examined. Separately, a coated plate (test piece) was prepared in the same manner using the composition of Example 4, and each resistance was examined. The test results are shown in Table 2, and all of the coated plates were practically sufficient. In particular, the coated plate of Example 6 was more excellent in alcohol resistance, gasoline resistance, and weather resistance.

[0033]

[Table 2]

[0034]

The chlorinated polypropylene-containing resin composition of the present invention comprises a chlorinated polypropylene and a (meth) acrylate, a hydroxyl group-containing (meth) acrylate,
It is a chlorinated polypropylene-containing acrylic composition comprising one or more monomer mixtures selected from α, β-unsaturated carboxylic acids and an antioxidant blended therein. Compared with acrylic resin, it has extremely excellent storage stability, and can be used for coating polypropylene for various uses, and a paint excellent in weather resistance can be obtained.

Claims (5)

[Claims] 1. A chlorinated polypropylene comprising one or more monomer mixtures selected from (meth) acrylates, hydroxyl-containing (meth) acrylates and α, β-unsaturated carboxylic acids. A chlorinated polypropylene-containing resin composition obtained by blending an antioxidant with a chlorinated polypropylene-modified acrylic resin. 2. Oxidation of a chlorinated polypropylene-modified acrylic resin comprising a chlorinated polypropylene and a mixture of one or more monomers selected from (meth) acrylates and α, β-unsaturated carboxylic acids. A chlorinated polypropylene-containing resin composition containing an inhibitor. 3. The amount of the antioxidant to be added to the chlorinated polypropylene-modified acrylic resin is 50 to 100,000 pp.
3. The chlorinated polypropylene-containing resin composition according to claim 1, wherein m is m. 4. The compounding ratio of the chlorinated polypropylene to the monomer mixture is from 5/95 to 40/60.
3. The chlorinated polypropylene-containing resin composition according to any one of 3. 5. The chlorinated polypropylene-containing resin composition according to claim 1, wherein an antioxidant and a radical promoter are blended with the chlorinated polypropylene-modified acrylic resin.