JPS63139903A - Modified copolymer and its application - Google Patents

Abstract

PURPOSE:To obtain the title polymer which is excellent in adhesion of coating, resistance to pitting and gasoline and useful as a coat forming element, by halogenating a modified ethylene random copolymer produced by the graft- polymerization of an ethylenic random copolymer with an unsaturated carboxylic acid derivative. CONSTITUTION:100pts.wt. ethylenic random copolymer having a mean molecular weight of 300-10,000 and a Q value of at most 4, obtained by copolymerizing 30-75mol% ethylene with 70-25mol% 30-20C alpha-olefin, is graft-polymerized with 0.2-50pts.wt. unsaturated carboxylic acid derivative such as a 3-10C unsaturated carboxylic acid and acid anhydride or esters thereof [e.g. (meth) acrylic acid (methyl ester), maleic anhydride, etc.] to give a modified ethylenic random copolymer having a limiting viscosity 0.01-0.6dl/g (in decalin at 135 deg.C; the same applies hereinafter). The obtained copolymer is reacted with a given amount of halogen in the presence of a catalyst such as an organic peroxide in a solvent at 30-150 deg.C to give a halogenated modified ethylenic random copolymer having a halogen content of 2-70wt% and a limiting viscosity of 0.01-0.6dl/g.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel halogenated modified ethylene random copolymer and its use as a coating film forming element.

[Prior art and its problems] Molded products made of polyolefin such as polypropylene, automobile bumpers made of polypropylene and synthetic rubber, etc.
Surface treatment agents (primers) suitable for undercoating molded products made of other materials and improving the adhesion and adhesion of paints, etc. to the surface include: prescribed propylene-ethylene,
solution of chlorinated polypropylene containing carboxyl groups (see Japanese Patent Publication No. 50-10916), ■ solution of halogenated polypropylene containing carboxyl groups (Special Publication No. 50-4231)
(see JP-A No. 58-118809, Japanese Patent Application Laid-Open No. 118809-1983), and furthermore, those containing a specified chlorinated product of a carboxyl group-modified propylene polymer (JP-A No. 60-9913).
(see Japanese Patent Publication No. 49-40864), and (2) those containing chlorinated polypropylene or chlorinated polyethylene (see Japanese Patent Publication No. 49-40864). However, there is a need for a primer that has even better coating film adhesion to the object to be coated.

In addition, for example, a paint film using a primer such as the one commonly used (■) cannot absorb enough impact when an impact is applied to the painted surface, causing the base material of the object to be coated to crack (
chipping). This is thought to be due to the high glass transition temperature of the resin material for the coating film.

Chlorinated polyolefins such as those used in (2) are also added to various paints as film adhesion imparting agents. Paints with such adhesion agents added are so-called one-coat paints that do not use a primer, but their adhesion properties are still insufficient and their impact resistance at low temperatures is also unsatisfactory due to their low flexibility. Furthermore, it has poor gasoline resistance, and cannot be said to be fully satisfactory for use, for example, on the exterior of automobiles.

[Means for solving problems]

The present inventor has conducted various studies in view of the current state of primers and adhesion promoters, and has discovered that it is effective to use a specific new halogenated modified ethylene random copolymer, and has completed the present invention. I was able to do that.

[Summary of the invention]

The present invention uses ethylene and α-
A modified ethylene random copolymer in which an unsaturated carboxylic acid derivative component consisting of an unsaturated carboxylic acid having 3 to 10 carbon atoms, its acid anhydride, and its ester is graft copolymerized to an ethylene random copolymer composed of an olefin. A halogenated modified ethylene random copolymer obtained by further halogenating a polymer,
(i) The ethylene component of the ethylene random copolymer is 30 to 75 mol% and the α-olefin component is 25% by mole.
(ii) The grafting ratio of the unsaturated carboxylic acid derivative component is in the range of 0.2 to 50 parts by weight based on 100 parts by weight of the liquid ethylene random copolymer. (iii) the halogen content of the halogenated modified ethylene random copolymer is in the range of 2 to 70% by weight, and (iv) the halogenated modified ethylene random copolymer is heated at 135°C. Intrinsic viscosity [η] measured in decalin is 0
．． A halogenated modified ethylene random copolymer characterized by the following: Ol to 0.6 d1/g is defined as a material invention, and a coating film forming element made of the halogenated modified ethylene random copolymer is defined as a use invention. shall be.

[Halogen ratio-modified ethylene random copolymer] The halogenated modified ethylene random copolymer of the present invention (hereinafter referred to as
(sometimes simply abbreviated as (C)) is derived from an ethylene-based random copolymer (hereinafter sometimes simply abbreviated as (A)) consisting of ethylene and an α-olefin having 3 to 20 carbon atoms. be done. Commonly used and preferable examples of [A] include, for example, JP-A-57-11759, which is obtained by the production method described in JP-A-57-123205, filed by the present applicant.
The ethylene/α-olefin copolymer described in Publication No. 5 can be used as is.

That is, as (A), 30 to 75 mol% of ethylene, preferably 40 to 60 mol% of ethylene α
- It is an olefin copolymer. The α-olefins that are copolymerization components include propylene, l-butene, 1-pentene, l-hexene, 1-octene, 1-decene, l-
Dodecene, l-tetradecene, 1-hexadecene, 1-
These are α-olefins having 3 to 20 carbon atoms such as octadecene and 4-methyl-1-pentene, and these may be composed of two or more types.

Among these, α-olefins having 3 to 14 carbon atoms are particularly preferred, and ethylene/α-olefin copolymers containing α-olefins having 3 to 8 carbon atoms as constituent components are particularly preferred.

The number average molecular weight of the ethylene/α-olefin copolymer is
Usually 300 to 10,000, preferably 500 to 8,000. Further, the Q value (~/In = weight average molecular weight/number average molecular weight) is usually 4 or less, preferably 3 or less, and preferably shows a statistical molecular weight distribution.

The ethylene content in the ethylene/α-olefin copolymer is measured by 3C-NMR analysis.

The number average molecular weight was calculated using G
PC (Gel Permeation Chromat
ograph). In addition, the Q value is calculated using a standard material with a known molecular weight (monodisperse polystyrene Mw500-8
40X10', 16 pieces) using GPC (Get P
Ermeation Chro-matograph
) counts, molecular weight and EV (Elution).
Create a correlation diagram (calibration curve) for Volume ). Then, take a GPC pattern of the sample using the GPC method,
After determining the molecular weight from the calibration curve, the Q value is calculated. Furthermore, statistical molecular weight distribution is one that shows a log-normal distribution or a distribution close to this, such as that of a copolymer obtained directly by polymerization, and a substantial amount, for example, 10% by weight or more of low molecular weight components (and/or or high molecular weight components) are not cut. Note that these measurement methods are the same below.

In order to obtain (C) of the present invention, the above-mentioned (
A modified ethylene random copolymer (hereinafter simply referred to as (B)) in which an unsaturated carboxylic acid derivative component consisting of an unsaturated carboxylic acid having 3 to 10 carbon atoms, an acid anhydride thereof, and an ester thereof is graft copolymerized to A). (Sometimes abbreviated as.)
It is necessary to obtain

The manufacturing method of CB), the unsaturated carboxylic acid derivative components used, grafting conditions, etc., and the preferable physical properties of CB) are disclosed in Japanese Patent Application Laid-Open No. 126120/1989 filed by the present applicant.
Examples include those described in the publication No.

Specifically, the unsaturated carboxylic acid derivative units having 3 to 10 carbon atoms which are the graft copolymerization components of the modified ethylene random copolymer CB) include acrylic acid, methacrylic acid, maleic acid, and fumaric acid. , itaconic acid, citraconic acid, tetrahydrophthalic acid, unsaturated carboxylic acids such as bicyclo(2,2,1)hept-2-ene-5,6-dicarboxylic acid, maleic anhydride, itaconic anhydride, citraconic anhydride, Tetrahydrophthalic anhydride, bicyclo(2,2,1) hept-2-ene-5,
Anhydrides of unsaturated carboxylic acids such as 6-dicarboxylic anhydride, methyl acrylate, methyl methacrylate, dimethyl maleate, monomethyl maleate, diethyl fumarate, dimethyl itaconate, dimethyl citraconate, dimethyl tetrahydrophthalate, Bicyclo(2,2,1
) Examples include esters of unsaturated carboxylic acids such as dimethyl hept-2-ene-5,6-dicarboxylate.

The intrinsic viscosity [η] of the modified ethylene random copolymer (B) measured in decalin at 135°C is usually 0.01 to 0.6 dl/g, preferably 0.03 to 0.
．． It is in the range of 5 dl/g.

Further, the number average molecular weight of the modified ethylene random copolymer (B) is usually in the range of 300 to 10,000, preferably 500 to 8,000. Further, the molecular weight distribution (1&/F4n) of the modified ethylene random copolymer (B) measured by gel permeation chromatography (GPC) is usually 4 or less, preferably 3 or less.

It should be noted that the grafting amount of the unsaturated carboxylic acid derivative in (B) needs to be such that the grafting amount of the unsaturated carboxylic acid derivative contained in (C) in the final stage falls within the range described below. Although it varies depending on the halogen content, it is usually in the range of 0.2 to 50 parts by weight, preferably 0.8 to 30 parts by weight, per 100 parts by weight of (A).

(C) of the present invention is obtained by further halogenating the above (B). Examples of the halogen include fluorine, chlorine, bromine, and iodine, and two or more of these may be used. Among these, chlorine is preferred.

Halogenated modified ethylene random copolymer of the present invention (
C) can be produced by reacting the modified ethylene random copolymer (B) with a halogen. The halogenation reaction can be carried out, if necessary, in the presence of a catalyst commonly used in halogenation reactions, or in the presence of a solvent that dissolves (B). Examples of catalysts include organic peroxides such as benzoyl peroxide and di-t-butyl peroxide, azobis(cyanoalkanes) such as α,α'-azobisisobutylnitrile and abcyclohexenecarbonitrile, light, and especially organic peroxides. Examples include ultraviolet light and water, and examples of the solvent include carbon tetrachloride, benzene, chlorinated benzene, chloroform, tetrachloroethane, and dichlorofluoromethane. The temperature during the reaction is usually in the range of 30 to 150°C, preferably 50 to 120°C, and the time required for the reaction can be selected arbitrarily. In the halogenation reaction, the halogen content of the produced halogenated modified ethylene random copolymer (C) is from 2 to 70.
It is carried out until reaching % double star, preferably in the range of 10 to 50% by weight. The halogenation reaction can be carried out by a batch method, a continuous method or a semi-continuous method. The desired product (C) can be obtained by treating the reaction mixture after completion of halogenation according to a conventional method.

In (C) of the present invention, the range of each mol% of the ethylene component and α-olefin component (total of both is 100 mol%) is the same as in (A) above. , when the ethylene component unit exceeds the upper limit (
If the adhesion with the polypropylene polymer in C) is insufficient, and if the value is below the lower limit, the impact absorption ability will be insufficient when an impact is applied to the coated surface at low temperatures, causing the base material of the coated object to crack. Since it becomes easier, it is necessary to be within this range.

Furthermore, the grafting ratio of the unsaturated carboxylic acid component in (C) varies depending on the halogen content in [C), but it needs to be 0.2 to 50 parts by weight per 100 parts by weight of (A) above. The content is preferably 0.8 to 30 parts by weight; however, if the upper limit is exceeded, the compatibility with pigments, paints, other vehicles, etc. will be insufficient, and if it is below the lower limit, when used as a primer. Adhesion to the paint or the object to be painted is insufficient. Further, the content of halogen in (C) needs to be in the range of 2 to 70% by weight, preferably in the range of 10 to 50% by weight. When the upper limit is exceeded, the hardness of (C) increases,
Shock absorbing power at low temperatures becomes insufficient, and below the lower limit, solubility in solvents and compatibility with paints etc. become insufficient. Also, the limiting viscosity [η] of (C) is 0.0
It is necessary to be in the range of 1 to 0.6 aj/g, and more preferably in the range of 0.02 to 0.45. If the resin exceeds the upper limit, it will not be compatible with paint or other vehicles, and if the resin falls below the lower limit, the strength of the resin itself will decrease, resulting in insufficient adhesion to the substrate. Also (C)
~/ll (n is preferably 4 or less, more preferably 3 or less. If it exceeds 4, the compatibility with paints and other vehicles may be insufficient, or the adhesion may be insufficient. Become.

The unsaturated carboxylic acid derivative component and the halogen component contained in (C) of the present invention are mainly randomly bonded to carbon atoms on the molecular chain or branch of the raw material (A).

[Use invention]

(C) of the present invention is useful as a coating film forming element. This film-forming element includes (i) when the present invention forms a film together with other components in the paint by adding (C) to a normal paint as a film adhesion imparting agent, (ii) ) May be used as a paint vehicle (color vehicle) to form a paint film. In (ii), it may occupy the majority of the vehicle or may be used together with other vehicles. In addition to primers, finishing (top coat) paints,
There are various types including one coat paint.

[Coating film forming element as coating film adhesion imparting agent] [
Examples of paints to which C] can be added as a film adhesion imparting agent include the following. These paints generally consist of vehicles such as paint resins as film-forming elements, pigments, solvents, and other components, and although it varies depending on the type of paint, (C) of the present invention is in a proportion of 100 parts by weight of the vehicle. It is usually added in a proportion of 1 to 200 parts by weight. Paints include various festivals, various paints, oil-based paints such as enamel, cellulose paints such as nitrocellulose lacquer, acrylic lacquer, acetyl cellulose lacquer, and lacquer base paints, phenolic resin paints, alkyd resin paints, amino alkyd resin paints, and vinyl paints. Examples include various synthetic resin paints and synthetic resin base paints such as chlorinated rubber paints, epoxy resin paints, acrylic resin paints, unsaturated polyester resin paints, polyurethane resin paints, and silicone resin paints. Among these, it is preferable to use it for synthetic resin paints, especially alkyd resin paints, aminoalkyd resin paints, epoxy resin paints, acrylic resin paints, unsaturated polyester resin paints, polyurethane resin paints, and the like.

That is, for example, the (C) of the present invention may be applied to a polyurethane resin paint.
) to which a coating film adhesion imparting agent is added, for example, PP base resin, RIM urethane, sheet mold compound (
When used for coating products made of SMC), etc., the adhesion of the coating film is good, and the low-temperature impact resistance (chipping resistance) is also greatly improved.

Therefore, it can be used as a one-coat paint, which has the advantage of eliminating the need for a primer.

[Coating film forming elements as vehicle]

The (Cl) of the present invention can also be used as a paint vehicle. In this case, the paint vehicle may consist only of (C), but other vehicle components, such as the various synthetic resin paints mentioned above, may be used. Synthetic resins, C1 polypropylene, CX unsaturated carboxylic acid-modified polyolefins, ethylene-vinyl acetate copolymers, ethylene-propylene copolymers, ethylene-acrylic acid ester copolymers, etc. are used as vehicles together with (C). In the case where they together form a vehicle, the amount of other vehicle components is preferably 200 parts by weight or less per 100 parts by weight of (C), but is not limited thereto.

When a paint using (C) of the present invention as a vehicle component is used as a primer or a paint other than a primer for products such as the above-mentioned PP resin or RIM urethane, it has excellent paint film adhesion for the primer or top coat. Moreover, it has excellent chipping resistance and gasoline resistance.

Hereinafter, the present invention will be explained by examples.

(1) Adhesion It was conducted according to the cross-cut test in JIS 5400-1979. The goban is 1. The 0 judgment made with each as is 1.
It shows how many of the 00 gobans were glued together.

(2) Water resistance After immersing the test piece in pure water at 40°C for 240 hours, changes in the appearance of the outer coating layer were visually observed to evaluate adhesion.

(3) Gasoline resistance The coated object was immersed in regular gasoline at room temperature for 24 hours, and changes in appearance were visually observed.

The judgment criteria are as follows.

O No blistering or peeling of the paint film is observed △ Slight blistering of the paint film is observed × Significant blistering or peeling of the paint film is observed (4)
After the initial compatibility of the paint was left at room temperature for 3 hours, the condition of the paint was visually observed.

The evaluation criteria are as follows.

Uniform state with no O phase separation or formation of gel-like substances △ State of slight phase separation After being left at room temperature for one month, the condition of the paint was visually observed. The evaluation criteria are
Same as initial compatibility.

(6) Surface gloss 60 listed in JIS K 5400-1979
The measurement was carried out according to the degree of specular gloss.

<7) Low-temperature impact resistance Painted 3M thick polypropylene (trade name Mitsui Petrochemicals Polypro A load of 1 kg was dropped from above 50 CIl, and the condition of the coating film and base material was visually inspected. The evaluation criteria are as follows.

○ Neither the coating film nor the base material cracked △ The coating film cracked, but the base material did not crack × Both the coating film and the base material cracked Examples 1 to 4, Comparative Examples 1 to 4 Halogenated as shown in Table 1 A solution obtained by dissolving the modified ethylene random copolymer (C) in the solvent shown in the table using a disk and bar was applied to various base materials of three dragon thickness that had been degreased shown in Table 1 using air spray. Approximately 10μ thick (when dry)
After standing at room temperature for 10 minutes, the paint shown in Table 1 was applied using air spray to a dry thickness of about 40 μm.

After leaving it for another 10 minutes, it was baked for 30 minutes using air open at 120°C. Table 1 shows the results of evaluating the coating film performance after 2 days of curing.

Examples 5 to 8, Comparative Examples 5 to 7 The halogenated modified ethylene random copolymer [C) shown in Table 2 was mixed into the chlorinated polypropylene shown in Table 2 using a disper? 8, and toluene was further added to prepare a liquid mixture having the solid content shown in Table 2. This liquid was applied on the W material shown in Table 2 in the same manner as in Example 1. still,
Unlike Example 1, the paint was baked at 120°C and 30°C.
I went in minutes. Table 2 shows the evaluation results of coating film performance. Table 2 also shows the evaluation results of the compatibility of the mixed liquid.

Examples 9 and 10, Comparative Example 8 A predetermined amount of the halogenated modified ethylene random copolymer (C) shown in Table 3 was mixed and dispersed in the paint shown in Table 2 using a disper to prepare a top coat. Using that paint,
It was applied onto the substrate shown in Table 2 using air spray so that the dry film thickness was about 45μ, and after being left for 10 minutes,
Baking was carried out for 30 minutes in an open air at ℃. Table 3 shows the coating film performance evaluated after 2 days of curing. Table 3 also shows the results of evaluating the compatibility of the top coat paints.

Claims (2)

[Claims] (1) An ethylene-based random copolymer composed of ethylene and an α-olefin having 3 to 20 carbon atoms, an unsaturated carboxylic acid having 3 to 10 carbon atoms, an acid anhydride thereof, and an ester thereof. A halogenated modified ethylene random copolymer obtained by further halogenating a modified ethylene random copolymer graft-copolymerized with a saturated carboxylic acid derivative component, comprising: (i) the ethylene random copolymer; The ethylene component of the polymer is 30 to 75 mol% and the α-olefin component is 25% by mole.
(ii) The grafting ratio of the unsaturated carboxylic acid derivative component is in the range of 0.2 to 50 parts by weight based on 100 parts by weight of the liquid ethylene random copolymer. (iii) the halogen content of the halogenated modified ethylene random copolymer is in the range of 2 to 70% by weight, and (iv) the halogenated modified ethylene random copolymer is heated at 135°C. Intrinsic viscosity [η] measured in decalin is 0
．． 01 to 0.6 dl/g. (2) An ethylene-based random copolymer composed of ethylene and an α-olefin having 3 to 20 carbon atoms is combined with an unsaturated carboxylic acid having 3 to 10 carbon atoms, its acid anhydride, and its ester. A halogenated modified ethylene random copolymer obtained by further halogenating a modified ethylene random copolymer graft-copolymerized with a saturated carboxylic acid derivative component, comprising: (i) the ethylene random copolymer; The ethylene component of the polymer is 30 to 75 mol% and the α-olefin component is 25% by mole.
(ii) The grafting ratio of the unsaturated carboxylic acid derivative component is in the range of 0.2 to 50 parts by weight based on 100 parts by weight of the liquid ethylene random copolymer. (iii) the halogen content of the halogenated modified ethylene random copolymer is in the range of 2 to 70% by weight, and (iv) the halogenated modified ethylene random copolymer is heated at 135°C. Intrinsic viscosity [η] measured in decalin is 0
．． A coating film-forming element comprising a halogenated modified ethylene random copolymer characterized by: