JP3429907B2 - Method for producing modified olefin polymer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a modified olefin polymer having excellent coating and adhesive properties, and a method for producing a modified olefin polymer. The present invention relates to a production method with less occurrence. [0002] Olefin-based polymers are widely used as general-purpose resins, but are difficult to coat and adhere. A method of modifying with an organic compound having a functional group for the purpose of improving paintability and adhesion is widely known (for example, JP-A-59-75914, JP-A-58-13).
643, JP-A-58-191706 and JP-A-61-27
2217). In particular, it has been found that modification with an organic compound having a hydroxyl group is effective as an effect on urethane coating (Japanese Patent Application Laid-Open No. 58-191706). On the other hand, examples of the modification method include a melting method using an extruder or the like, a solution method, a suspension method, and the like. The melting method is widely used because of simplicity of post-treatment. When modified by a melting method using an organic compound having a hydroxyl group, there are the following problems. The organic compound having an unsaturated bond is self-polymerized in addition to being grafted to form a homopolymer. Since the melting method does not usually have a step of removing such by-products, the resulting modified product contains some impurities. Further, when the modification is carried out by using an extruder, if the production is continued for a long time, a homopolymer is deposited on an inner wall of the extruder, a screw, or the like, and there is a problem that the homopolymer is mixed into the modified product as a foreign substance. There is a screen mesh as a method for removing foreign matter, but since a large amount of foreign matter is generated,
Frequent screen mesh replacement is required, which is problematic in productivity. [0003] The present invention is directed to a method for producing a modified olefin polymer which suppresses the generation of foreign substances, reduces contamination, and does not require frequent replacement of the screen mesh. It is. [0004] The above-mentioned problem is solved by the following method. That is, in a method of heating and kneading (A) an olefin polymer, (B) an organic compound having at least one unsaturated bond in a molecule and having a hydroxyl group, and (C) an organic peroxide. , (A) 0.1 to 50 parts by weight of an oligomer having a hydroxyl group at a terminal is mixed with 100 parts by weight of an olefin polymer to produce foreign matter by a method for producing a modified olefin polymer. And a modified olefin polymer with less contamination can be obtained. Hereinafter, the present invention will be described in detail. (A) Olefin Polymer The olefin polymer used in the present invention includes ethylene homopolymer, propylene homopolymer,
Random or block copolymers of ethylene and propylene and random or block copolymers of ethylene and / or propylene with at most 7 other α-olefins (copolymerization ratio of α-olefin is at most 20% by weight). The molecular weight of these olefin polymers is generally 2 to 1,000,000, and 2 to 5
It is preferable that the olefin resin has a molecular weight of 100,000, and more preferably 50,000 to 300,000. In addition, low density (0.900 g / cm
³ ) to high density (0.980 g / cm ³ ) ethylene homopolymer, propylene homopolymer, random or block copolymer of ethylene and propylene, and random or block of ethylene or propylene and another α-olefin Copolymers are preferred. These olefin polymers may be used alone or in combination of two or more. Further, two or more of these olefin polymers may be used as a resin blend at an arbitrary ratio. (B) An organic compound having at least one unsaturated bond in the molecule and having a hydroxyl group (hereinafter also referred to as a hydroxyl group-containing organic compound) The organic compound used in the present invention has at least one hydroxyl compound in the molecule. It is a compound having one unsaturated bond and containing a hydroxyl group. Typical examples thereof include an alcohol having a double bond, an alcohol having a triple bond, an ester of a monovalent or divalent unsaturated carboxylic acid with an unsubstituted dihydric alcohol, and an ester of the unsaturated carboxylic acid with an unsubstituted divalent alcohol. Examples include esters with substituted trihydric alcohols, unsubstituted tetrahydric alcohols, or unsubstituted pentahydric alcohols. Of these, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl methacrylate are preferred because they are easily graft-modified and relatively inexpensive. (C) Organic peroxide The organic peroxide used in the present invention is generally used as an initiator in radical polymerization and as a crosslinking agent for the polymer, and has a one-minute half-life temperature of 100 ° C. or more. Are preferred. If the one-minute half-life temperature is lower than 100 ° C., not only is it difficult to handle, but also the effect of use is lower than that of 100 ° C. or higher, which is not preferable. Representative examples of preferred organic peroxides include 1,1-
Ketone peroxides such as bis-tert-butylperoxy-3,3,5-trimethylcyclohexane, alkyl peroxides such as dicumyl peroxide, 2,
Examples include diacyl peroxides such as 5-dimethylhexane-2,5-hydroperoxide and benzoyl peroxide, and peroxyesters such as 2,5-dimethyl-2,5-dibenzoylperoxyhexane. (D) Oligomers having hydroxyl groups at the terminals (hereinafter also referred to as hydroxyl-containing oligomers) The oligomers having a hydroxyl group at the terminals in the present invention are:
An oligomer having a hydroxyl group at at least one terminal in one molecule. The number average molecular weight of the oligomer having a hydroxyl group at the terminal is from 300 to 10,000, preferably from 500 to 8,000, and a liquid rubber or waxy solid is preferred. If the number average molecular weight exceeds 10,000, it is not preferable because the paintability and adhesion, which are the objectives of the modified product, are adversely affected. The oligomer having a hydroxyl group at its terminal may have an unsaturated bond.
The iodine value of the oligomer is preferably from 0 to 50,
More preferably, it is 0 or more and 10 or less. When the iodine value is lower, the generation of foreign substances can be reduced during the modification, and a modified product having excellent paintability and adhesion, which is the purpose of the modified product, can be obtained. The number of hydroxyl groups of the oligomer in the present invention may be at least one at the terminal in one molecule,
It may be present at both ends of the linear oligomer. If it is a branched oligomer, it may be present at all terminals. The oligomer having a functional group at these terminals can be produced by a known method. Examples of these include hydrogen-terminated hydrogenated 1,4-polybutadiene, hydroxy-terminated 1,2-polybutadiene, hydroxy-terminated hydrogenated 1,2-polybutadiene, and the like. (E) Mixing ratio In producing the modified product of the present invention, the mixing ratio of the hydroxyl group-containing organic compound to 100 parts by weight of the olefin polymer is 0.1 to 30 parts by weight, preferably 0.1 to 30 parts by weight. 2
To 10 parts by weight. If the amount is less than 0.1 part by weight, the object of the modified product, that is, coating property and adhesion cannot be improved, and if the amount exceeds 30 parts by weight, the amount of unreacted hydroxyl group-containing organic compound increases and bleed out after molding, etc. It is not preferable because it has an adverse effect. The mixing ratio of the organic peroxide to 100 parts by weight of the olefin polymer is 0.01 to 20 parts by weight, and preferably 0.05 to 10 parts by weight. 0.01
If the amount is less than 10 parts by weight, the coating properties and adhesiveness, which are the objectives of the modified product, cannot be improved. If the amount exceeds 20 parts by weight, the melt flow rate of the modified product becomes too high due to visbreak, and the mechanical properties are significantly reduced. Therefore, it is not preferable. The mixing ratio of the oligomer having a hydroxyl group at the terminal to 100 parts by weight of the propylene-based polymer is 0.1 to 50.
Parts by weight, preferably 0.5 to 30 parts by weight.
If the amount is less than 0.1 part by weight, the effect of preventing foreign substances from being mixed, which is the object of the present invention, cannot be sufficiently obtained. The appearance deteriorates significantly. Furthermore, for the purpose of improving the paintability and adhesion of the modified product, organic tin
And / or tertiary amines can be added. (F) Production Method The modified product of the present invention can be produced by melt-kneading the above-mentioned mixture. Melt kneading is generally performed using a Banbury mixer, kneader, rotor mill,
And a mixer such as a screw extruder. The kneading temperature varies depending on the type of the organic peroxide used, but is generally 1 which is the melting point of the olefin polymer.
It is performed in a range of 30 ° C to 300 ° C. The present invention will be described in more detail with reference to the following examples. [Olefin polymer] As an olefin polymer, J
A propylene homopolymer having a melt flow rate of 0.5 g / 10 min measured based on IS K6758 was used. [Hydroxyl-containing organic compound] As the hydroxyl-containing organic compound, 2-hydroxyethyl methacrylate (hereinafter referred to as HEMA) was used. [Organic peroxide] As the organic peroxide, 1,
3-Bis- (t-butylperoxyisopropyl) -benzene (Percadox 14 manufactured by Kayaku Akzo Co., Ltd.) was used. [Oligomer Having Hydroxyl Group at Terminal] As the hydroxyl group-containing oligomer, a 1,4-polybutadiene having a hydroxyl group terminal (polyether H, manufactured by Mitsubishi Chemical Corporation) was used (hereinafter, referred to as oligomer A). Each of the formulations shown in Table 1 was mixed for 5 minutes using a super mixer. The resulting mixture was melt-kneaded using a twin screw extruder having a screw diameter of 40 mm and an L / D of 42. The set temperature was set at 180 ° C. After cleaning the inside of the extruder, a screen mesh of 80 mesh was attached to the die. The discharge rate was set to 20 kg / hour. From the start of the production, an increase in the resin pressure in the extruder due to clogging of the screen mesh by foreign substances was observed, and the time until the resin pressure reached 30 kg / cm ² was measured. Further, the obtained modified product was injection-molded, a two-component urethane paint (R271 paint manufactured by Nippon Bee Chemical Co., Ltd.) was applied, and the peeling strength at 180 ° was measured according to JIS K 6854 to evaluate the coatability. The flexural modulus and flexural strength of the molded article were measured according to ASTM D790. (Examples 1 to 7) Table 1 shows production conditions and evaluation results of the modified olefin polymer. (Comparative Examples 1 to 7) Table 2 shows production conditions and evaluation results of the modified olefin polymer. [Table 1] [Table 2] According to the method for producing a modified product of the present invention, the homopolymer is less deposited on the inner wall and the screw of the extruder even if the production is continued for a long time as compared with the conventional method. The amount that is mixed in is also reduced. As a result, the number of replacements of the screen mesh is reduced, and productivity is remarkably improved.

Continuation of front page (56) References JP-A-55-50007 (JP, A) JP-A-1-272603 (JP, A) JP-A-5-239220 (JP, A) JP-A-6-256430 (JP) JP-A-6-345829 (JP, A) JP-A-7-126334 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08F 255/00

Claims (1)

(57) Claims: (A) an olefin polymer, (B) an organic compound having at least one unsaturated bond in a molecule and having a hydroxyl group, and (C) Heating the organic peroxide,
In the kneading method, (A) the olefin polymer 10
A method for producing a modified olefin polymer, wherein 0.1 to 50 parts by weight of (D) an oligomer having a hydroxyl group at a terminal is mixed with 0 part by weight.