JP2000327730A - Resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition which can be spray-coated in a high concentration without causing a separation phenomenon, gives coating films having excellent weather ability, and is useful for coatings, primers and adhesives, by compounding a polyolefin and an acrylic resin having polymerizable unsaturated bonds in the molecule. SOLUTION: This resin composition comprises (A) 10 to 90 pts.wt. of a polyolefin (for example, the homopolymer or copolymer of ethylene, propylene, 1-butene, and the like, and a dienic polymer), and (B) 90 to 10 pts.wt. of an acrylic resin having polymerizable unsaturated bonds in the molecule (for example, an acrylic resin obtained by addition-polymerizing a carboxylic acid anhydride having a polymerizable bond in the molecule to an acrylic resin having hydroxyl groups in the molecule) (wherein the total amount of the components A and B is 100 pts.wt.). The composition is preferably obtained, for example, by mixing the component A with the component B in an A/B weight ratio of 1/9 to 9/1, heating the mixture at 80 to 200 deg.C, adding an organic peroxide and then subjecting the mixture to a graft reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an acrylic-modified polyolefin-based resin composition. More specifically, the present invention relates to a resin composition useful as a paint and primer for an untreated polyolefin-based resin film or sheet, or a molded product, or as an adhesive or the like.

[0002]

2. Description of the Related Art Conventionally, polyolefin resins generally have many advantages such as high productivity, excellent moldability, light weight, rust prevention and impact resistance. Interior and exterior, home appliances and furniture,
Widely used as miscellaneous goods and building materials.

[0003] Such polyolefin-based resin molded products are generally non-polar and different from polar synthetic resins represented by polyurethane resins, polyamide resins, acrylic resins and polyester resins. Because it is crystalline, it is very difficult to apply and bond it to a general-purpose resin composition.

[0004] For this reason, when a polyolefin resin molded article is coated or bonded, its surface is treated with a primer or activated to improve the adhesion to the surface. For example, in the case of a bumper for automobiles, the surface of the bumper is etched with a halogen-based organic solvent such as trichloroethane to enhance the adhesion with the coating film, or after a pretreatment such as a corona discharge treatment, a plasma treatment, or an ozone treatment. At
The desired coating and bonding have been performed.

[0005] However, coating and bonding using these conventionally known general-purpose resin compositions not only require enormous equipment costs, but also require a long time to perform, and the finish is not uniform. This was a cause of the difference in the surface treatment condition.

Conventionally, as a coating composition which solves the above-mentioned problems, for example, a composition comprising maleic acid introduced into a polyolefin (Japanese Patent Publication No. 62-21027) or a chlorinated modified polyolefin as a main component Such compositions (for example, Japanese Patent Publication No. 50-10916) have been proposed. However, these are excellent in adhesion to polyolefin-based molded articles and the like, but are inferior in weather resistance. Therefore, they are usually limited to use for primers or in places where weather resistance is unnecessary. . Therefore, in the case of using these compositions to apply paint to places where weather resistance is required, usually a two-coat finish is required, which requires complicated operations.

[0007] For this reason, a paint capable of one-coat finish treatment which can exhibit excellent adhesion to a material without any pretreatment and has excellent weather resistance has been developed. In the field, for example, a resin obtained by copolymerizing an acrylic monomer and a chlorinated polyolefin (JP-A-58-71966, etc.), or a hydroxyl group-containing acryl-chlorinated polyolefin copolymer and an isocyanate compound Coating compositions (JP-A-59-27968) and the like have been proposed.

Further, a method for introducing an unsaturated bond into a polyolefin (JP-A-1-123812 and JP-A-2-123812)
69109, etc.), a method of introducing an organic peroxide (Japanese Patent Application Laid-Open No. 1-131220, etc.), and a method of using a bifunctional organic peroxide (Japanese Patent Application Laid-Open No. 64-36614, etc.) are also proposed. These are devises for improving the reactivity between the polyolefin and the radical polymerizable unsaturated monomer.

However, in the above-mentioned resin composition and its production method, in many cases, the reaction must be carried out at a dilute concentration due to the problem of viscosity, and the graft copolymerization efficiency to polyolefin is low, and the radical polymerizable unsaturated Since a homopolymer of a monomer is easily generated, the obtained resin solution is very easily separated, and usually has a drawback that the resin solution cannot be used immediately.

[0010]

SUMMARY OF THE INVENTION The present invention provides a novel resin composition which solves the above-mentioned conventional problems. That is, the present invention is capable of spray coating in a high concentration state without causing a separation phenomenon of the resin solution, and the obtained coating film is more excellent than the chlorinated modified polyolefin-based coating film. An object of the present invention is to provide a resin composition which exhibits weather resistance and is useful as a paint and primer for an untreated polyolefin-based resin film or sheet, or a molded product, or as an adhesive.

[0011]

Means for Solving the Problems The present inventors have made intensive studies and studies on a resin composition that can achieve the above object, and have found that, in particular, the use of an acrylic resin having a polymerizable unsaturated bond in the molecule, Furthermore, it is very effective to use a carboxylic anhydride-added acrylic resin in which a carboxylic anhydride having a polymerizable unsaturated bond in the molecule is added to an acrylic resin having a hydroxyl group, and this is a specific polyolefin. Resin composition consisting of ratio and formula,
They have found that they are extremely useful, and have completed the present invention.

That is, the present invention provides a polyolefin (A) of 10 to 90 parts by weight and an acrylic resin (B) of 90 to 1 having a polymerizable unsaturated bond in a molecule.
A resin composition containing 0 parts by weight (however, the total amount of (A) and (B) is 100 parts by weight), 10 to 90 parts by weight of polyolefin (A), and Resin having polymerizable unsaturated bond (B) 90-1
0 parts by weight (provided that the total amount of (A) and (B) is 100 parts by weight), and the reaction is carried out in the presence of an organic peroxide. The resin composition according to the above, wherein the acrylic resin (B) having a polymerizable unsaturated bond in the molecule is formed by adding a polymerizable unsaturated bond to the acrylic resin having a hydroxyl group in the molecule. The resin composition according to any one of the above items, wherein the resin composition is an acrylic resin to which a carboxylic acid anhydride is added.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The polyolefin (A) used in the resin composition of the present invention includes ethylene, propylene, 1-butene, 1-heptene, 1-octene, 1-hexene, 1-decene, and 4-olefin. Examples thereof include homopolymers such as methyl-1-pentene, and copolymers thereof, and dienes such as butadiene. Also, in particular,
In the case of producing a coating composition used for coating a material to be coated made of polypropylene, it is preferable to use polypropylene or a copolymer in which the propylene component accounts for 50 mol% or more.

The polyolefin preferably has a weight average molecular weight (hereinafter abbreviated as Mw) in the range of 5,000 to 200,000. That is, if the Mw is less than 5,000, the obtained resin composition tends to have poor adhesion to the material, and if the Mw exceeds 200,000, it is used as a solvent during resin synthesis. At the time of dissolution, even if the concentration is relatively low, the liquid becomes a highly viscous liquid, and it becomes difficult to produce a target resin composition. Therefore, it is preferable to use a polyolefin in the above range.

In the present invention, the acrylic resin (B) having a polymerizable unsaturated bond in the molecule is usually from 60 to 150.
In an organic solvent heated to ℃, a mixture of a radical polymerizable monomer having a hydroxyl group in the molecule, a radical polymerizable monomer having no hydroxyl group in the molecule, and a polymerization initiator is fed and polymerized to have a hydroxyl group. A resin obtained by obtaining an acrylic resin and adding thereto a carboxylic anhydride having a polymerizable unsaturated bond in the molecule (hereinafter, abbreviated as a carboxylic anhydride-added acrylic resin). However, the present invention is not limited to this range.

Here, the hydroxyl value of the acrylic resin having a hydroxyl group is preferably from 3 to 200 KOH mg / g, and more preferably from 5 to 150 KOH mg / g.

The addition of a carboxylic anhydride having a polymerizable unsaturated bond in the molecule is carried out within a range of 1 to 100% of the hydroxyl group in the acrylic resin having a hydroxyl group.

As the organic solvent, aromatics such as xylene, toluene and ethylbenzene, hexane, heptane,
Examples include aliphatic hydrocarbons such as octane and decane; alicyclic hydrocarbons such as cyclohexane, cyclohexene and methylcyclohexane; aliphatic alcohols such as ethanol and isopropyl alcohol; and ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone. Also, a mixture of two or more of these may be used. Among these, aromatic hydrocarbons and aliphatic hydrocarbons are preferably used.

Examples of the radical polymerizable monomer having a hydroxyl group in the molecule include hydroxyethyl acrylate and 2-hydroxyethyl (meth) acrylate.

The radical polymerizable monomer having no hydroxyl group in the molecule includes aromatic vinyls such as styrene, α-methylstyrene, vinyltoluene, t-butylstyrene, acrylic acid, methacrylic acid, maleic acid, and the like. Carboxyl group-containing vinyls such as maleic anhydride and itaconic acid, and their monoesters, methyl (meth)
Acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth)
Acrylate, stearyl (meth) acrylate, tridecyl (meth) acrylate, lauroyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, dimethylammonoethyl (meth) acrylate, diethylaminoethyl ( (Meth) acrylates such as (meth) acrylate, hydroxyethyl acrylate and 2-hydroxyethyl (meth) acrylate, and other acrylonitrile, methacrylonitrile, vinyl acetate,
Examples include vinyl propionate, acrylamide, methacrylamide, methylolacrylamide, and methylolmethacrylamide.

Further, as a polymerization initiator, di-tert-
Butyl peroxide, tert-butyl peroxy-
Organic peroxides such as 2-ethylhexanoate, benzoyl peroxide, dicumyl peroxide, lauroyl peroxide, tert-peroxybenzoate, cumene hydroperoxide, azoisobutylnitrile, 4,4′-azobis (4 -Cyanopentaic acid),
An azo compound such as 2,2′-azobis (2-methyl-N- (2-hydroxyethyl) propioamide) is exemplified.

Examples of the carboxylic anhydride having a polymerizable unsaturated bond in the molecule include maleic anhydride, tetrahydrophthalic anhydride, dodecenyl succinic anhydride and the like.

In the present invention, the carboxylic anhydride-added acrylic resin obtained as described above and the polyolefin (A) are mixed in a weight ratio (polyolefin / carboxylic anhydride-added acrylic resin) of 1/9 to 9/1. , More preferably in the range of 2/8 to 8/2, and at a temperature of 80 to 2
After the temperature is adjusted to 00 ° C., an objective resin composition can be obtained by adding an organic peroxide and performing a graft reaction.

The organic peroxide includes di-tert.
-Butyl peroxide, tert-butyl peroxy-2-ethylhexanoate, benzoyl peroxide, dicumyl peroxide, lauroyl peroxide, tert-peroxybenzoate, cumene hydroperoxide and the like. Among them, di-t
tert-Butyl peroxide and tert-butylperoxy-2-ethylhexanoate are preferably used.

The amount of the organic peroxide to be used is generally in the range of 5 to 50% by weight, more preferably 5 to 50% by weight, based on the total weight of the polyolefin and the carboxylic anhydride-added acrylic resin.
It is in the range of 30% by weight. When the amount of the organic peroxide used is less than 5% by weight, the resin solution obtained tends to be easily separated. On the contrary, when the amount used exceeds 50% by weight, gelation occurs during the reaction. It is preferable to use an organic peroxide in the above-mentioned range because the above-mentioned range is easily used. Also, this organic peroxide takes as much time as possible,
It is preferable to add this little by little. In other words, depending on the amount used, in general, when the organic peroxide is added in a lump, the reaction solution is relatively easily gelled, so that the reaction solution is required to take a small amount of time or a large number of times. It is preferable to add separately in small amounts.

The resin composition of the present invention thus obtained can be used as it is as a paint or an adhesive, and further, if necessary, various stabilizers such as an antioxidant, a weather resistance stabilizer and a heat resistance inhibitor. It does not matter if a component such as a coloring agent such as an inorganic pigment or an organic pigment, or a conductivity-imparting agent such as carbon black or ferrite is contained.

The composition of the present invention may be, for example, a polyolefin such as polyethylene, polypropylene and polystyrene, an ethylene-propylene copolymer, an ethylene-butene copolymer, a propylene-butene copolymer and an ethylene-propylene copolymer.
Molded articles made of olefin copolymers such as propylene-butene copolymers, and can be suitably used as an overcoat of molded articles made of polypropylene and synthetic rubber, further polyamide resin, unsaturated polyester resin, polycarbonate resin, Furthermore, it can also be used for surface treatment of a steel sheet, an electrodeposition-treated steel sheet, and the like.

The resin composition of the present invention is also useful as an undercoating agent such as a paint or an adhesive mainly composed of a polyurethane resin, a polyester resin, a melamine resin, an epoxy resin, and the like. It can be used to improve the adhesion of a paint or the like to the surface of an object and to form a coating film having more excellent clarity and the like.

In particular, the resin composition of the present invention can be used as a top coat for molded articles made of polyolefin such as polypropylene, molded articles made of polypropylene and synthetic rubber, molded articles made of unsaturated polyester, epoxy resin, polyurethane resin and the like. Alternatively, it can be suitably used as an undercoat for improving the adhesion of a paint to the surface of these molded articles.

The application of the resin composition of the present invention to the surface of a molded article or the like is not particularly limited. However, it is more preferable to apply the composition by spray coating. It can be sprayed and painted. The coating can be easily performed at room temperature, and the drying method after the coating is not particularly limited, and it can be dried by an appropriate method such as natural drying or forced drying by heating.

The composition of the present invention can be applied to a wide range of uses other than its use as a coating material of the above-mentioned molded article due to its characteristics. It is also possible to apply the paint by electropainting, spray painting, brush painting or the like. The paint used is not particularly limited, and may include a solvent-type thermoplastic acrylic resin paint, a solvent-type thermosetting acrylic resin paint, an acrylic-modified alkyd resin paint, an epoxy resin paint, a polyurethane resin paint, and a melamine resin paint. it can.

The resin composition of the present invention can be suitably used not only as a paint or a primer but also as an adhesive or a paint additive.

[0033]

EXAMPLES The resin composition of the present invention will be further described below with reference to production methods and various test examples. In the following, parts and percentages are by weight unless otherwise specified.

Examples 1 to 12 Synthesis of Acrylic Resin Added with Carboxylic Anhydride In a four-necked flask equipped with a stirrer, a thermometer, a reflux cooling device, and a nitrogen inlet tube, a column described in the column of Acrylic Resin Synthesis shown in Table 1 was prepared. A solvent was charged and heated to 100 ° C. while replacing with nitrogen. Next, a mixed solution of the monomer and the polymerization initiator described in the column of synthesis of an acrylic resin shown in Table 1 was fed thereto over 4 hours. 0.4 parts of hexanoate (hereinafter abbreviated as PBO) is added,
It was left for another 2 hours. Thereafter, the same kind of solvent as used in the above synthesis was added, and the mixture was diluted until the nonvolatile content became 50%. While maintaining the temperature at 100 ° C., the carboxylic anhydride described in the column of carboxylic anhydride addition shown in Table 1 was added,
After reacting for 1 hour, a carboxylic anhydride-added acrylic resin was synthesized.

Production of Resin Composition The polyolefin and the solvent described in the column of the graft reaction shown in Table 1 were charged into the carboxylic anhydride-added acrylic resin solution obtained in the synthesis example of the acrylic resin, and the temperature was changed to 135 while replacing with nitrogen. The temperature was raised to ° C. Next, di-tert-butyl peroxide (hereinafter abbreviated as PBD), which is an organic peroxide described in the column of the graft reaction shown in Table 1, and the amount thereof were added thereto. In addition, in the addition of PBD, of the amounts shown in Table 1, first 3/7 of the amount was added, 2/7 after 1 hour, and 2/7 after 1 hour. And the reaction was carried out in three total portions. After allowing to react for 2 hours after the addition of PBD, a solvent of the same type as the above solvent was added, and the non-volatile content was 3%.
After dilution to 0%, a resin composition of the present invention was obtained.

The types and Mw of the polyolefin used in Examples 1 and 5 to 12 are those of Best Plast BP750 (trade name, manufactured by Huls Japan K.K., Mw = 70000). In Example 3, a product of Bestplast BP708 (trade name, manufactured by Huls Japan K.K., Mw = 45000) was used. (Ube Industries, Ltd. product name, Mw = 30000) was used.

COMPARATIVE EXAMPLES 1 AND 2 Resin compositions were prepared in the same manner as in Examples 1 to 12, except that the raw materials and amounts for producing the resin composition were reacted as shown in Table 2. I got The polyolefin used in these comparative examples is Vestplast BP750 (trade name, manufactured by Huls Japan K.K., Mw = 70000). Further, as is clear from Table 2, the weight ratio of polyolefin / carboxylic acid anhydride-added acrylic resin in these comparative examples was 9/10 in Comparative Example 1.
In Comparative Example 2, the resin composition was manufactured to be 930/100.

Comparative Example 3 A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen inlet tube was charged with 60 parts of toluene and 40 parts of xylene.
And 85 parts of Supercron 813A (trade name, manufactured by Nippon Paper Industries Co., Ltd.), which is a chlorinated polyolefin,
The temperature was raised to 85 ° C. while replacing with nitrogen. Next, 20 parts of styrene, 20 parts of butyl acrylate, and 40 parts of butyl methacrylate as radical polymerizable monomers
Parts, methyl methacrylate 15 parts, methacrylic acid 1
And a mixture of 1 part of PBO as a polymerization initiator was fed over 2 hours. After completion of the feed, 4 hours and 5 hours later, 0.5 part of PBO was added, and the mixture was allowed to stand for 2 hours to obtain an acryl-modified chlorinated polyolefin.

Comparative Example 4 The procedure of Comparative Example 3 was repeated except that the amount of the chlorinated polyolefin was changed from 85 parts to 22 parts to obtain an acrylic-modified chlorinated polyolefin.

Comparative Example 5 An acryl-modified chlorinated polyolefin was obtained in the same manner as in Comparative Example 3, except that the amount of the chlorinated polyolefin was changed from 85 parts to 10 parts.

The above Examples 1 to 12 and Comparative Examples 1 to 5
Were evaluated by the following items. The respective evaluation methods are as follows.

Viscosity of Resin Composition Solution The obtained resin composition was adjusted to have a nonvolatile content of 20% with the same type of solvent used at the time of its production, and was prepared according to the method described in JIS K 5400. , Ford Cup No. 4 was used to measure the number of seconds dropped at 25 ° C. Table 3 shows the results.

Stability of Resin Solution The obtained resin composition solution was allowed to stand for one week under conditions of a nonvolatile content of 30% and 40 ° C., and the state of the solution was evaluated. After a lapse of one week, the resin composition solution in which neither separation nor precipitation was confirmed was evaluated as ○, and the one in which separation and / or precipitation was observed was evaluated as ×.

Sprayability of resin solution Using a coating gun (Wider spray gun (trade name: W-88-13H5G) manufactured by Iwata Coating Machine Industry Co., Ltd.), atomization pressure 4 kg / cm ² , nozzle opened one rotation, At a temperature of 30 ° C. in the coating booth, the resin composition solutions obtained in Examples and Comparative Examples were sprayed, and it was observed whether or not stringing occurred. However, what occurred was indicated as x, and is shown in Table 3.

Cross-cut peeling test, measurement of peel strength, weather resistance test The obtained resin composition solution was mixed with a solvent of the same kind as that used at the time of their production, and was subjected to Ford Cup No. 2 at 25 ° C. 4
Was adjusted so that the number of seconds of falling in the sample was 15 ± 2 seconds. Then, a product made of polypropylene (made by Grand Polymer Co., Ltd., product name: J70) whose surface was wiped with isopropyl alcohol
The above solution is spray-coated on the square plate of 5) such that the film thickness after drying is 10 μm to form a coating film.
A cross-cut peel test and a weather resistance test were performed. In addition, a white top coat (Nippon Bee Chemical Co., Ltd.)
R278 (main agent) / R271 (curing agent) =
8/2) to form a coating film by drying so that the film thickness after drying is 20 μm, and then left at room temperature for 10 minutes.
The coating film subjected to a baking treatment in an oven at 100 ° C. for 30 minutes was subjected to a cross-cut peel test, a measurement of peel strength, and a weather resistance test. Table 3 shows the results obtained in the above test. In addition, the cross-cut peeling test result after overcoating was 0 /
In the case of 100, the peel strength was not measured.

Cross-cut peel test In accordance with the method of the cross-cut peel test described in JIS-K-5400, a cross-cut test piece is prepared, and cellotape (Nichiban Co., Ltd.) is placed on the cross-cut. After pasting,
Immediately pull in 90 ° direction to peel off,
The evaluation was made based on the number of grids that were not peeled out of 0 pieces.

Measurement of Peeling Strength A cut was made in the coated substrate at a width of 1 cm, and the edge was peeled off. The edge was pulled in the direction of 180 ° at a speed of 50 mm / min, and the peeling strength was measured. Strength is 600g / c
m or more, ◎, 300-600 g / cm, and less than 300 g / cm, x.

A weather resistance test was carried out using a sunshine carbon arc lamp according to the accelerated weather resistance test method described in JIS-K-5400, and a 60-degree specular gloss after 500 hours (JIS-K
-5400), the retention of the measured value (%) = (gloss after the test / initial gloss) × 100 was calculated.
The results are shown in Table 3 as Δ when the value is 60% or more and less than 80%, and as X when the value is less than 60%.

[0049]

[Table 1]

[0050]

[Table 2]

[0051]

[Table 3]

[0052]

As apparent from the above description, especially from the results of the examples, the resin composition of the present invention is very stable and can be used immediately without any separation or precipitation. It is possible. Moreover, it is excellent in spray workability in a high-concentration state, and is particularly excellent in adhesiveness to a polyolefin resin molded product, and has a function and effect unique to the present invention, which has not been obtained before.

Further, a coating film made of the resin composition of the present invention has excellent weather resistance and is most suitable for use as a paint or a primer.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 133/04 C09D 133/04 C09J 123/02 C09J 123/02 133/04 133/04 (72) Inventor Koichi Machida 1900 Togo, Mobara-shi, Chiba Prefecture Mitsui Chemicals Co., Ltd. (72) Inventor Tsukasa Murakami 1900, Togo, Togo, Mobara-shi, Chiba Mitsui Chemicals Co., Ltd. EK046 EK056 FD146 GH01 GJ01 4J027 AA01 CB03 CC02 CD08 CD09 4J031 AA12 AA20 AB02 AC01 AE03 AE13 AF12 4J038 CB021 CB081 CB111 CG141 CH121 CJ031 CJ101 CJ131 CP041 CP071 DL04 DA041 MA10

Claims (4)

[Claims] 1. A polyolefin (A) of 10 to 90 parts by weight and an acrylic resin (B) having a polymerizable unsaturated bond in a molecule of 90 to 10 parts by weight (provided that the total amount of (A) and (B) is 100 parts by weight)). 2. 10 to 90 parts by weight of a polyolefin (A) and 90 to 10 parts by weight of an acrylic resin (B) having a polymerizable unsaturated bond in a molecule (provided that the total amount of (A) and (B) is 100 parts by weight).
The resin composition as described in the above. 3. The resin composition according to claim 2, wherein the reaction is carried out in the presence of an organic peroxide. 4. The acrylic resin (B) having a polymerizable unsaturated bond in the molecule is an acrylic resin obtained by adding a carboxylic anhydride having a polymerizable unsaturated bond in the molecule to an acrylic resin having a hydroxyl group in the molecule. The resin composition according to any one of claims 1 to 3.