JPH07196979A - Resin composition for paint - Google Patents

Abstract

(57) [Summary] [Structure] 5-40% by weight of styrene, 10-85% by weight of (meth) acrylic monomer copolymerizable therewith, and chlorine content
Chlorinated polyolefin resin up to 50% by weight 10 to 50% by weight
(A), a urethane-modified polyester polyol (B) having a number average molecular weight of 650 to 60,000 chain-extended with a diisocyanate compound, and a crosslinkable resin (C) capable of reacting with a hydroxyl group. A weight ratio of 15/85 to 95/5, and an isocyanato group in component C,
A coating resin composition in which the equivalent ratio of the hydroxyl groups in component A to component B is 0.1 to 2. [Effect] The paint using this composition can be directly applied to polyolefin materials by one-coat method. The paint film has a well-balanced solvent resistance in addition to the finished appearance, adhesion and weather resistance. , Excellent in chemical resistance, elongation and workability.

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 paints which, when applied to a polyolefin-based material, has a well-balanced coating film with excellent solvent resistance, chemical resistance, elongation and processability.

[0002]

[Prior Art and its Problems] Polyolefin resin is
Excellent properties such as chemical resistance, ozone resistance, heat resistance,
It is widely used as an industrial material for household appliances, automobile parts, etc. because it has water resistance, good electrical properties, etc., and is lightweight and inexpensive. By the way, since the polyolefin-based material itself is non-polar and crystalline, it has the drawback of being inconvenient in terms of coating and adhesion.

On the other hand, it is known to introduce a polar group into the surface of a polyolefin-based material by plasma treatment, or to wash the surface with 1-trichloroethane, subject it to primer treatment, and then topcoat. But,
Both require tedious operations, and the latter
In terms of environmental pollution, we have no choice but to use harmful solvents, and neither is satisfactory.

Further, as a resin composition for paint, for example,
With acrylic modified chlorinated polyolefin containing isobornyl (meth) acrylate, one-coat coating can be applied, and the coating film has finished appearance, adhesion, solvent resistance,
It is disclosed that it has excellent chemical resistance and weather resistance (Japanese Patent Laid-Open No. 117574/1993). However, in this method, by crosslinking only the hydroxyl groups in the (meth) acrylic monomer and the crosslinking resin, the coating film obtained is improved in terms of solvent resistance, chemical resistance, etc. Membranes cannot adequately follow the elongation and processability characteristics of polyolefin-based materials. In this type of resin composition, when the elongation and processability of the coating film are to be obtained, the solvent resistance and chemical resistance thereof are lowered, and it is very difficult to balance these performances.

In the present invention, one-coat coating can be applied directly to a polyolefin-based material sheet or a molded product, and the coating film has a good balance in terms of appearance, adhesion, and weather resistance, and particularly well-balanced solvent resistance. It is an object of the present invention to provide a coating resin composition having excellent chemical resistance, elongation and processability.

[0006]

[Means for Solving the Problems] As a result of intensive studies for solving the above problems, the present inventors have found that an acrylic-modified chlorinated polyolefin resin having a specific composition comprising a graft copolymer and a homopolymer is obtained. The present inventors have found the fact that blending a urethane-modified polyester polyol having a specific molecular weight in a specific ratio is effective, and have reached the present invention.

That is, the present invention comprises 5 to 40% by weight of styrene and 10 to 85% of (meth) acrylic monomer copolymerizable therewith.
%, And a mixture (A) comprising 10 to 50% by weight of a chlorinated polyolefin resin having a chlorine content of 50% by weight or less, and a number average molecular weight 650 to 60,0 chain-extended with a diisocyanate compound.
The urethane-modified polyester polyol (B) of 00 and a crosslinkable resin (C) capable of reacting with a hydroxyl group are contained, and the weight ratio of the component A and the component B is in the range of 15/85 to 95/5 and in the component C. A coating resin composition, wherein the equivalent ratio of the isocyanato group to the hydroxyl groups in component A and component B is in the range of 0.1 to 2. In the present specification, (meta)
Acrylic monomer, (meth) acrylate and (meth) acrylic acid mean methacrylic monomer, acrylic monomer; methacrylate, acrylate; methacrylic acid, acrylic acid.

First, the component A of the present invention is a mixture of a graft copolymer and a homopolymer obtained by solution polymerization of styrene and a (meth) acrylic monomer in the presence of a chlorinated polyolefin resin. . In the present invention, it is essential to use the chlorinated polyolefin resin in the above-mentioned solution polymerization stage, and it is not preferable to use it as a single component in the other stages. By the way, styrene and (meta)
In the case of a mixture obtained by blending a chlorinated polyolefin resin after solution polymerization of an acrylic monomer, the coating film finally obtained is inferior in terms of adhesion.

In the above solution polymerization for preparing the component A of the present invention, known organic solvents and polymerization initiators are used. Examples of the organic solvent include aromatic hydrocarbon solvents such as toluene, xylene, and solvent naphtha; ester solvents such as ethyl acetate and butyl acetate; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of the polymerization initiator include organic peroxides such as benzoyl peroxide and t-butyl peroxyacetate; and azo compounds such as azobisisobutyronitrile used in combination therewith.

In the component A of the present invention, the (meth) acrylic monomer copolymerizable with styrene is classified into those containing a hydroxyl group and those not containing a hydroxyl group. These may be used alone or in combination of two or more. Here, as the monomer having a hydroxyl group, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate , 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, (meth) acrylate of ring-opening adduct of ε-caprolactone, and 3-chloro-2-hydroxypropyl acrylate. Examples of the monomer containing no hydroxyl group include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, Lauryl (meth) acrylate, 2-
Examples thereof include ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, and (meth) acrylic acid.

In the component A of the present invention, the chlorinated polyolefin resin is a polyethylene resin, a polypropylene resin and / or an ethylene / propylene copolymer having a chlorine content of 50% by weight or less, preferably a chlorine content of 30% by weight. It is possible to use a product in which 30% by weight or less of an unsaturated bond is introduced. When this chlorine content exceeds 50% by weight, the adhesion of the coating film to the polyolefin-based material that is the object to be coated and its weather resistance will deteriorate.

The composition of styrene, (meth) acrylic monomer and chlorinated polyolefin resin in the component A of the present invention is as follows.
The total of these is 100% by weight, and the ranges are 5 to 40% by weight, 10 to 85% by weight and 10 to 50% by weight, respectively. If the content of styrene is less than 5% by weight, the glossiness of the coating film obtained will decrease, and if it exceeds 40% by weight, the adhesion of the coating film will be impaired, and the coating film will become hard, leading to a decrease in elongation and processability. . Further, when the content of the chlorinated polyolefin resin is less than 10% by weight, the adhesiveness of the coating film sharply decreases, and when it exceeds 85% by weight, the coating film causes cohesive failure.

Next, the urethane-modified polyester polyol which is the component B of the present invention has a number average molecular weight of 650 to 60,0.
It is 00, and the polyester polyol synthesized from carboxylic acid and glycols is chain-extended with a diisocyanate compound and has a urethane bond in its molecular chain.
When the number average molecular weight of component B is less than 650, the resulting coating film lacks elongation and processability. When the molecular weight exceeds 60,000, the coating film exhibits excellent elongation and processability, but its solvent resistance is low. Be damaged. The urethane bond in the polyester is effective for balancing the solvent resistance, elongation and processability of the coating film.

Here, examples of the carboxylic acid include unsaturated carboxylic acids such as maleic anhydride, maleic acid, fumaric acid and itaconic acid; terephthalic acid, isophthalic acid, phthalic anhydride, naphthalenedicarboxylic acid, succinic acid and glutaric acid. Acid, adipic acid, azelaic acid, 1,10-decanedicarboxylic acid, cyclohexanedicarboxylic acid, trimetic acid,
Examples thereof include saturated polycarboxylic acids such as sebacic acid and oxalic acid. Examples of glycols include ethylene glycol, diethylene glycol, 1,3-propanediol,
1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, propylene glycol, 1,6-hexanediol, 1,10-decanediol, 3-methyl-pentanediol, 2,2'- Dimethyl-1,3-propanediol, neopentyl glycol, trimethylolethane, trimethylolpropane, glycerin, pentaerythritol, ethylene oxide adduct of bisphenol A, bisphenol A
And the propylene oxide adduct thereof.

As the diisocyanate compound,
For example, aromatic compounds such as tolylene diisocyanate, xylylene diisocyanate and diphenylmethane diisocyanate; aliphatic compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate and trimethylhexamethylene diisocyanate; isophorone diisocyanate, methylcyclohexane-2,4-diisocyanate, methylcyclohexane -2,6-diisocyanate,
4,4-methylenebis (cyclohexyl isocyanate),
Examples thereof include alicyclic compounds such as 1,3-di (isocyanatomethyl) cyclohexane.

In the present invention, the above-mentioned components A and B are used.
The weight ratio of and should be in the range of 15/85 to 95/5. When this weight ratio is less than 95/5, the solvent resistance of the coating film is improved, but the elongation and workability are impaired, and when it is 15/85 or more, the adhesion of the coating film is sharply impaired. Furthermore, the sum of the hydroxyl values of the components A and B of the present invention is 5 to 80 mg-KO.
Make sure it is in the range of H / g. This hydroxyl value is 5 mg-KO
When it is less than H / g, the solvent resistance and chemical resistance of the coating film are poor,
If it exceeds 80 mg-KOH / g, the solvent resistance and chemical resistance are improved, but the elongation and workability of the coating film are drastically reduced.

Further, as the crosslinkable resin capable of reacting with the hydroxyl group which is the component C of the present invention, an isocyanate prepolymer, a blocked isocyanate compound thereof or the like can be used. Here, examples of the isocyanate prepolymer include an isocyanurate body, a biuret body, and an adduct body derived from the diisocyanate compound in the component B. The blocked isocyanate compound is an isocyanate prepolymer in which an isocyanate group is blocked with a blocking agent. As the blocking agent, phenol type, lactam type, oxime type,
Any of imine type, active methylene type, acid amide type, imide type, sulfite type and the like can be used, but phenol type, lactam type, oxime type and imine type blocking agents are preferable. Specific examples thereof include phenol, cresol, xylenol, nitrophenol, chlorophenol, ethylphenol, p-hydroxydiphenyl, t-butylphenol, o-isopropylphenol, o-sec-butylphenol, p-nonylphenol, pt-t-. Phenolic blocking agents such as octylphenol, hydroxybenzoic acid, and hydroxybenzoic acid ester; ε-caprolactam, δ-palerolactam, γ
-Lactam blocking agents such as butyrolactam and β-propiolactam; oxime blocking agents such as formamide oxime, acetaldoxime, acetoxime, methyl ethyl ketoxime, diacetyl monooxime, benzophenone oxime, cyclohexanone oxime; ethyleneimine, propyleneimine, etc. Imine-based blocking agents of

In the present invention, the amount of the isocyanato group in the component C is in the range of 0.1 to 2 equivalents relative to 1 equivalent of the hydroxyl groups in the component A and the component B. If it is less than 0.1 equivalent, a sufficiently crosslinked coating film cannot be obtained, and its solvent resistance and chemical resistance decrease, and if it exceeds 2 equivalents, the coating film has excellent solvent resistance and chemical resistance. However, its elongation and workability sharply decrease.

The resin composition of the present invention containing the above-mentioned component A, component B and component C is used as a top coat for sheets and molded products of polyolefin-based materials and as a paint obtained as described below. You can here,
Examples of the polyolefin-based material include those composed of homopolymers or copolymers of α-olefins such as ethylene, propylene, 1-butene, and 3-methyl-1-heptene.

The method for making the resin composition of the present invention into a paint is as follows:
According to a known method, that is, the above resin composition may be mixed with a pigment and, if necessary, various additives and a solvent for dilution, and kneaded and dispersed by using a sand mill, a ball mill, a paint shaker or the like. Here, as the pigment,
Inorganic coloring pigments such as titanium dioxide, carbon black and iron oxide; organic coloring pigments such as phthalocyanine blue and quinacridone red; organic coloring pastes carrying inorganic pigments, and additives such as leveling agents and ultraviolet rays. Examples thereof include absorbers, light stabilizers, antioxidants, anti-settling agents, antistatic agents, surface conditioners, and the like. In addition, in the method of applying the obtained paint, first, the polyolefin-based material is degreased with isopropyl alcohol. After that, the material may be coated with the above-mentioned coating material by a known method, for example, by spraying or brushing, so as to form 1 coat-1 bake type, 2 coat-1 bake type and the like.

[0021]

EXAMPLES The present invention will be described in detail below with reference to synthesis examples, examples and comparative examples. In the following, "part" and "%" are based on weight. In addition, the raw material and polymerization initiator used for the component A in the synthesis examples are shown by the following abbreviations. ST: styrene, MAc: methacrylic acid, MMA: methyl methacrylate, EA: ethyl acrylate, n-BA: n-butyl acrylate, n-BMA: n-butyl methacrylate, HEMA: hydroxyethyl methacrylate; BP
O: benzoyl peroxide, PBO: t-butylperoxy-2-ethylhexylnoate, AIBN: azobisisobutyronitrile.

Synthesis Example 1 100 parts of toluene and chlorinated polypropylene (Super Clone L206: trade name, manufactured by Nippon Paper Industries Co., Ltd., chlorine content 30%) were placed in a reaction vessel (with a stirrer, a thermometer, an air condenser and a nitrogen introducing tube). , Solid content 50%), 120 parts were charged, and 85
Raised to ℃ and kept. On the other hand, in another container, ST 28 parts, M
Ac 0.7 parts, MMA 11.2 parts and n-BMA 100 parts,
1.7 parts of PBO was dissolved. This dissolved substance was dropped into the above reaction vessel in 2 hours and reacted at 85 ° C. for 7 hours to obtain a nonvolatile content.
An acrylic modified chlorinated polyolefin (A-1) having 50% and a number average molecular weight of 2,600 was obtained. This composition is summarized in Table 1. Synthetic Examples 2 to 9, Synthetic Example 11, Synthetic Example 12, Synthetic Example 14 and Synthetic Example 15 In Synthetic Example 1, the amounts of chlorinated polyolefin and ST, and the types and amounts of (meth) acrylic monomer and polymerization initiator. In the same manner as in Tables 1 to 5, except that the acrylic modified chlorinated polyolefin (A-2
.About.A-9, A-11, A-12, A-14 and A-15) were obtained.

Synthetic Example 10 In Synthetic Example 1, the kind and amount of chlorinated polyolefin was changed to chlorinated polypropylene (Super Clone L206: trade name, manufactured by Nippon Paper Industries Co., Ltd., chlorine content 30%, solid content 50%).
Parts and chlorinated polypropylene (Super Clone 813
A: Product name, manufactured by Nippon Paper Industries, chlorine content 30%, solid content 50
%) Acrylic-modified chlorinated polyolefin (A-10) was obtained by completely the same operation except changing to 55 parts. This composition is summarized in Table 3.

Synthesis Example 13 In Synthesis Example 1, the type and amount of chlorinated polyolefin was changed to chlorinated polypropylene (Super Clone 507: trade name,
An acrylic-modified chlorinated polyolefin (A-13) was obtained in the same manner as in the above, except that the amount was changed to 150 parts by Nippon Paper Industries Co., Ltd., chlorine content 67%, solid content 40%). This composition is summarized in Table 4.

Synthesis Example 16 A reactor (with a stirrer, a thermometer, an air condenser and a nitrogen introducing tube) was charged with only 100 parts of toluene, and the temperature was raised to 85 ° C. and kept. On the other hand, in another container, ST 28 parts, MAc
0.7 parts, MMA 11.2 parts and n-BMA 100 parts, PB
1.7 parts of O were dissolved. This dissolved substance was dropped into the above reaction vessel in 2 hours and reacted at 85 ° C. for 7 hours. Chlorinated polypropylene (Super Clone L206: trade name, manufactured by Nippon Paper Industries, chlorine content 30%, solid content 50%) 120
The parts were mixed to obtain a blend (A-16) of an acrylic polymer having a nonvolatile content of 50% and a number average molecular weight of 2,200 and a chlorinated polyolefin. This composition is summarized in Table 5.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

[Table 3]

[0029]

[Table 4]

[0030]

[Table 5]

Synthesis Example 17 A reaction vessel (with a stirrer, a thermometer, an air condenser and a nitrogen introducing tube) was charged with 160 parts of adipic acid, 133 parts of neopentyl glycol and 0.01 part of dibutyltin oxide, and the mixture was heated at 220 ° C. for 1 hour and 200 hours. Perform the esterification reaction at 6 ° C for 6 hours and cool. Next, 9.0 parts of ethylene glycol, 88 parts of methyl ethyl ketone, 46.4 parts of isophorone diisocyanate and 0.
3 parts was added and the temperature was raised to 80 ° C. and maintained for 4 hours to obtain a urethane-modified polyester polyol (B-1) having a nonvolatile content of 80%, a viscosity of 31 poise and a number average molecular weight of 4,400. The composition is summarized in Table 6.

Synthesis Examples 18 to 24 In Synthesis Example 17, the types and amounts of polyhydric alcohol and dicarboxylic acid, and the amounts of diisocyanate and solvent are shown in Table 6.
-A urethane modified polyester polyol (B-2 to B-8) was operated in exactly the same manner except as shown in Table 7.
Got

[0033]

[Table 6]

[0034]

[Table 7]

Example 1 50 parts of urethane-modified polyester polyol (A-9) obtained in Synthesis Example 9 (40 parts in terms of solid content), 120 parts of acrylic-modified chlorinated polyolefin (B-1) obtained in Synthesis Example 17 (60 parts in terms of solid content), 59 parts of titanium oxide as a pigment and 22.5 parts of toluene were kneaded and dispersed by a paint shaker for 2 hours to obtain white enamel.
00 (trade name, manufactured by Mitsui Toatsu Chemicals, Inc., biuret modified product of hexamethylene diisocyanate, nonvolatile content 75%, isocyanate content 17%) was added to 5.7 parts to obtain a coating material. At this time, the ratio of the pigment and the solid content in the resin composition is 1.0 / 1.0.
It is a weight ratio. The composition of this paint, (A-9) / (B-1)
(Solid content weight ratio), hydroxyl value in (A-9) and (B-1), and isocyanato group in component C and (A-9) +
Table 8 summarizes the equivalent ratios of the hydroxyl groups in (B-1). Next, this paint was applied to a polypropylene plate (70 mm × 140 mm × 1 mm thick) that had been degreased with isopropyl alcohol in advance with a bar coater # 50, baked at 60 ° C for 30 minutes, and allowed to stand at room temperature for 5 days before testing. Serve on a board. The coating film physical properties of this test plate were evaluated by the following methods, and the results are shown in Table 15. Compatibility: Only the resin components (components A to C) were mixed and applied on a glass plate, allowed to stand in the room for 10 minutes, and then dried by heating at 60 ° C. for 30 minutes. At that time, a sample having no abnormality in transparency was evaluated as ◯ and evaluated by visual observation in three grades (◯, Δ, ×). -Finishing appearance: A film having a good glossy feeling on the test plate, no remarkable skin roughness, and no cissing, armpits, uneven color, or glossiness is evaluated as ○, and three levels are visually observed (○, Evaluation was made with Δ, ×). Adhesion: Adhesion of the coating film of the test plate was evaluated in three grades (○, Δ, ×) according to the grid pattern of JIS-K-5400 (1990.8.5.2).・ Gasoline resistance: Regular gasoline (Nisseki Silver: trade name, manufactured by Nippon Oil Co., Ltd.) is moistened with gauze at room temperature,
The coating film of the test plate was rubbed 100 times while the gasoline was kept dry, and the state of the coating film was visually observed. If there is no noticeable skin roughness and there is no abnormality such as gloss, ○
The evaluation was made in 3 grades (○, Δ, ×). -Acid resistance: 0.1 N-sulfuric acid 0.2 ml was dropped on the coating surface of the test plate, left standing at room temperature for 24 hours, washed with water, and the state of the coating surface was visually observed. The case where there was no remarkable rough skin and there were no abnormalities such as glossiness was rated as ◯ and evaluated in 3 grades (◯, Δ, x). -Alkali resistance: 0.2 ml of 0.1N-sodium hydroxide was dropped on the coating surface of the test plate, left standing at room temperature for 24 hours and washed with water, and the state of the coating surface was visually observed. The case where there was no remarkable rough skin and there were no abnormalities such as glossiness was rated as ◯ and evaluated in 3 grades (◯, Δ, x). -Water resistance: After immersing the test plate in pure water for 24 hours, the state of the coating film surface was visually observed. The case where there was no remarkable rough skin and there were no abnormalities such as glossiness was rated as ◯ and evaluated in 3 grades (◯, Δ, x). -Weather resistance: JIS-K-5400 (1990.9.8.1) Accelerated weather resistance test by sunshine carbon arc lamp type, and after 100 hours, 60 degree specular gloss (JIS-K-5400 (1990.7.6)) The retention rate (%) of the measured value = (glossiness after the test / initial glossiness) × 100 was calculated, and when the gloss retention rate was 80% or more and no discoloration was observed, the product was classified into three levels (○). ,
Evaluation was made with Δ, ×). -Elongation: The test plate was put in a dryer at 150 ° C for 1 minute and stretched to 3 times the length of the original test piece (elongation of 200%), and the state of the coating film surface at that time was visually observed. A sample having no adhesiveness, no remarkable skin roughness, and no abnormalities such as glossiness was evaluated as ◯ and evaluated in 3 grades (◯, Δ, ×).

Examples 2 to 19 In the same manner as in Example 1, except that the kinds and amounts of the components A and B and the amounts of the component C are as shown in Tables 8 to 11, the same operations were carried out to obtain coating materials. To obtain a test plate. The coating film physical properties were evaluated, and the results are shown in Table 15.

Comparative Examples 1 to 13 In the same manner as in Example 1, except that the kinds and amounts of the component A and the component B and the amount of the component C are as shown in Tables 12 to 14, the same operation was performed to obtain the coating composition. To obtain a test plate. The coating film physical properties were evaluated, and the results are shown in Table 16.

[0038]

[Table 8]

[0039]

[Table 9]

[0040]

[Table 10]

[0041]

[Table 11]

[0042]

[Table 12]

[0043]

[Table 13]

[0044]

[Table 14]

[0045]

[Table 15]

[0046]

[Table 16]

[0047]

EFFECTS OF THE INVENTION According to the present invention, a paint using the obtained resin composition can be directly one-coat coated on a polyolefin material, and the coating film has a finished appearance, adhesion and weather resistance. Of course, in particular, it has excellent balance in solvent resistance, chemical resistance, elongation and workability.

Claims (3)

[Claims] 1. Consists of 5 to 40% by weight of styrene, 10 to 85% by weight of a (meth) acrylic monomer copolymerizable therewith, and 10 to 50% by weight of a chlorinated polyolefin resin having a chlorine content of 50% by weight or less. The mixture (A), a urethane-modified polyester polyol (B) having a number average molecular weight of 650 to 60,000 chain-extended with a diisocyanate compound, and a crosslinkable resin (C) capable of reacting with a hydroxyl group, and a weight ratio of the component A and the component B. Is in the range of 15/85 to 95/5, and the equivalent ratio of the isocyanato group in component C to the hydroxyl group in component A and component B is
A resin composition for paints, which is in the range of 0.1 to 2. 2. The coating resin composition according to claim 1, wherein the total of the hydroxyl values in component A and component B is 5 to 80 mg-KOH / g. 3. The resin composition for coating composition according to claim 1, wherein the component A is a mixture of styrene, a graft copolymer of a (meth) acrylic monomer and a chlorinated polyolefin, and a homopolymer thereof.