JP3375668B2 - Modified low molecular weight polyolefin and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modified low molecular weight polyolefin and a method for producing the same, and more particularly to a modified low molecular weight polyolefin having a hydroxyl group and excellent in emulsifying property, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, a low molecular weight polyolefin is obtained by polymerizing an α-olefin such as ethylene or propylene by a medium-low pressure method in the presence of a transition metal catalyst containing titanium or vanadium as a main component, a so-called Ziegler catalyst. It is industrially produced by a method such as a direct production method or a method in which a high molecular weight polyolefin polymer polymerized by a high pressure method or an intermediate and low pressure method is reduced to a low molecular weight by a thermal degradation method or a radical degradation method. In addition, among these low molecular weight polyolefins, a method for producing a modified polyolefin is also known, in which low molecular weight polyethylene or low molecular weight polypropylene is graft-copolymerized with an unsaturated carboxylic acid such as maleic acid or maleic anhydride or a derivative thereof. (Japanese Patent Publication Sho 5
The modified low molecular weight polyethylene and modified low molecular weight polypropylene obtained by graft-copolymerizing the unsaturated carboxylic acid or its derivative, and the oxidized low molecular weight polyolefin are unmodified. Since it is more hydrophilic than low molecular weight polyolefin, it is easy to emulsify.

[0003]

However, in the method of obtaining a modified low molecular weight polyolefin by graft-copolymerizing the unsaturated carboxylic acid or its derivative, the low molecular weight polyethylene or the low molecular weight polyethylene is highly reactive, and At the time of the copolymerization reaction, gelation occurs to increase the melt viscosity, and turbidity may occur during dissolution.
Depending on the application, it may be difficult to use. Further, if the melt viscosity becomes higher, a reactor having a high stirring ability is required, which may cause a cost increase. Further, the oxidized low molecular weight polyolefin is produced by oxidizing the low molecular weight polyolefin wax with oxygen or the like, so that a carbonyl group, a carboxyl group, a hydroxyl group and the like are mixed in the molecule, and the presence of the carbonyl group reduces the weather resistance. ,Also,
With the esterification reaction of a carboxyl group and a hydroxyl group, the viscosity may increase with time during production, and workability may deteriorate when the product is taken out from the reactor.

Therefore, an object of the present invention is to selectively introduce only a hydroxyl group into a low-molecular-weight polyolefin, and to increase viscosity of a modified low-molecular-weight polyolefin excellent in emulsifying property by the hydroxyl group and a modified low-molecular-weight polyolefin thereof during production. It is to provide a method that can be manufactured without the above.

[0005]

In order to solve the above-mentioned problems, the present invention has an intrinsic viscosity [η] of 0.01 to 0.7 dl.
/ G of low molecular weight polyolefin , hydroxyl group in the ester part
Ri and a (meth) Na by polymerizing acrylic ester 1 to 40 wt% graft copolymer alone, the addition of water Emarujo
If you put it through a 100 mesh wire mesh
The ratio of non-emulsified product to solid content is less than 0.1% by weight
To provide a modified low molecular weight polyolefin.

[0006]

Further, according to the present invention, the intrinsic viscosity [η] is 0.01 as a method for producing the modified low molecular weight polyolefin.
And a low molecular weight polyolefin of ~0.7dl / g, Este
(Meth) acrylic acid ester having only a hydroxyl group in the polymer part is graft-copolymerized in a molten state to increase the viscosity during production.
The present invention also provides a method for producing the modified low-molecular-weight polyolefin without the use.

The modified low molecular weight polyolefin of the present invention and the method for producing the same (hereinafter referred to as "the method of the present invention") will be described in detail below.

The modified low molecular weight polyolefin of the present invention is
A low molecular weight polyolefin obtained by graft-copolymerizing an ethylenically unsaturated monomer having a hydroxyl group,
It has a main chain derived from the low molecular weight polyolefin and a side chain derived from the ethylenically unsaturated monomer.

The low molecular weight polyolefin forming the main chain of the modified low molecular weight polyolefin of the present invention is a homopolymer of an α-olefin having 2 to 12 carbon atoms or the 2-1 to 2 carbon atoms.
It is a random copolymer composed of a combination of two or more kinds of 2 α-olefins. Examples of the α-olefin having 2 to 12 carbon atoms include ethylene, propylene, butene-
1, pentene-1, 2-methylbutene-1, 3-methylbutene-1, hexene-1, 3-methylpentene-1,
4-methylpentene-1,3,3-dimethylbutene-
1, heptene-1, methylhexene-1, dimethylpentene-1, trimethylbutene-1, ethylpentene-
1, octene-1, methylpentene-1, dimethylhexene-1, trimethylpentene-1, ethylhexene-
1, methyl ethyl pentene-1, diethyl butene-1,
Propyl pentene-1, decene-1, methyl nonene-
1, dimethyloctene-1, trimethylheptene-1,
Ethyl octene-1, methyl ethyl heptene-1, diethyl hexene-1, dodecene-1, hexadodecene-1
Etc. Among these, a homopolymer or a copolymer composed of an α-olefin having 2 to 4 carbon atoms is preferable.

This low molecular weight polyolefin has an intrinsic viscosity [η] of 0.01 to 0.70 dl / g, preferably 0.02 to 0.60 dl / g, particularly in a molten state. 0.02 to 0.55 dl / in that a modified low molecular weight ethylene polymer having a melt viscosity in an appropriate range when being modified by graft copolymerization and having excellent mechanical properties such as hardness can be obtained. The range of g is preferable.

The low molecular weight polyolefin may be obtained by a known method, and its production method is not particularly limited. For example, a high-pressure radical polymerization method and a production method by polymerization such as medium / low pressure polymerization method performed in the presence of various transition metal compound catalysts such as Ziegler catalyst, and a high-molecular-weight polyolefin produced by the polymerization method Examples of the thermal decomposition method include production by degrading or radical degrading using a peroxide.

In the modified low-molecular-weight polyolefin of the present invention, the monomer graft-copolymerized as a side chain to the main chain derived from the low-molecular-weight polyolefin is a hydroxyl group-containing ethylenically unsaturated monomer (hereinafter, simply "Unsaturated monomer"). This unsaturated monomer is an unsaturated compound containing an ethylenic double bond and one or more hydroxyl groups in the molecule. Specific examples of this unsaturated monomer include (meth) acrylic acid ester having a hydroxyl group in the ester portion, unsaturated alcohol, a hydroxyl group-containing styrene derivative, hydroxyvinyl ether, and the like, and further N-methylolacrylamide, 2- Other examples include (meth) acryloyloxyethyl acid phosphate, glycerin monoallyl ether, and allyloxyethanol.

The (meth) acrylic acid ester having a hydroxyl group in the ester portion is a mono (meth) acrylate compound of a polyhydric alcohol, and specific examples thereof include hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth). Acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, glycerin mono (meth) acrylate, pentaerythritol mono (meth) acrylate, trimethylol Propane mono (meth) acrylate, tetraethyl ethane mono (meth) acrylate, butanediol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, etc. can be mentioned. That.

Examples of unsaturated alcohols include 10-undecen-1-ol, 1-octen-3-ol, 2-methanol norbornene, allyl alcohol and 2-butene-1,4-diol.

Examples of the hydroxyl group-containing styrene derivative include hydroxystyrene and the like.

Examples of the hydroxy vinyl ether include the following general formula (a):

[0018]

[Chemical 1]

A compound represented by the formula: wherein n is an integer of 0 to 2 and m is an integer of 1 to 4 is included. Specific examples of the hydroxy vinyl ether represented by the general formula (a) include hydroxymethyl vinyl ether, hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, hydroxymethyl propenyl ether, hydroxyethyl propenyl ether, hydroxypropyl propenyl ether,
Examples thereof include hydroxybutyl propenyl ether, hydroxymethyl butenyl ether, hydroxyethyl butenyl ether, hydroxypropyl butenyl ether and hydroxybutyl butenyl ether.

In the modified low molecular weight polyolefin of the present invention, one or more of these unsaturated monomers can be graft-copolymerized with the low molecular weight polyolefin at the same time.

Among these unsaturated monomers, a (meth) acrylic acid ester having a hydroxyl group in the ester part is
Highly reactive and easy to perform graft copolymerization,
It is preferable because it is easily available, and 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and 2-hydroxyethyl methacrylate are particularly preferable.

The content of the unsaturated monomer in the modified low-molecular-weight polyolefin of the present invention, that is, the grafting amount is advantageous in production, excellent in emulsifying property, has an appropriate molecular weight, and has sufficient mechanical properties. It is adjusted to 1 to 40% by weight, preferably 8 to 30% by weight, from the viewpoint of obtaining a modified low-molecular-weight polyolefin that exerts its effect.

The intrinsic viscosity [η] of the modified low molecular weight ethylene polymer of the present invention is usually 0.02 to 0.55 dl / g.
The density is usually 0.85 to 1.10.
It is about g / cm ³ .

The method for producing the modified low-molecular-weight polyolefin of the present invention can be appropriately selected according to the physical properties, application, etc. required of the modified low-molecular-weight polyolefin obtained. For example, a method of graft-copolymerizing the low molecular weight polyolefin and the unsaturated monomer in a molten state: a solution obtained by heating and dissolving the low molecular weight polyolefin in an organic solvent, the unsaturated monomer is sequentially added dropwise. Solution grafting method in which graft copolymerization is carried out, and an aqueous suspension method in which an unsaturated monomer and an organic peroxide are successively added dropwise to an aqueous suspension obtained by dispersing a low molecular weight polyolefin in water and graft copolymerization is carried out. Method etc. are mentioned.

Among these methods, a post-process such as a process of removing a dispersion medium such as an organic solvent and water is not required, so that a simple process can be carried out, and a low-molecular-weight polyolefin having a high degree of crystallinity. In terms of obtaining a modified low molecular weight polyolefin with a high grafting amount using, a low molecular weight polyolefin and the unsaturated monomer , particularly the ester part
A method of graft-copolymerizing a (meth) acrylic acid ester having a hydroxyl group in a molten state is preferable.

As a method for graft-copolymerizing a low molecular weight polyolefin and an unsaturated monomer in a molten state,
For example, low molecular weight polyolefin, unsaturated monomer and organic peroxide are put into a mixer such as a Henschel mixer or a blender, mixed, and the resulting mixture is put into a heating and melting apparatus such as an extruder to be mixed with an organic peroxide. A method of carrying out a graft copolymerization reaction at a temperature above the decomposition temperature of the substance and above the melting point of the low molecular weight polyolefin; placing the low molecular weight polyolefin in the reactor and heating at a temperature above the melting point and above the decomposition temperature of the organic peroxide used. After melting, a method of successively dropping an unsaturated monomer and an organic peroxide to carry out a graft copolymerization reaction; a low molecular weight polyolefin is impregnated with an unsaturated monomer and, if necessary, an organic peroxide. Examples of the method include a method of performing a graft copolymerization reaction by heating or irradiating an actinic ray. In these methods, the organic peroxide is not always necessary, and the graft copolymerization reaction can be performed even in the absence of the organic peroxide.

In these methods, the charging ratio of the low molecular weight polyolefin and the unsaturated monomer is usually
The ratio is 99.9 to 60 parts by weight of the low molecular weight polyolefin and 0.1 to 40 parts by weight of the monomer represented by the general formula (a).

When an organic peroxide is used in the above graft copolymerization, the organic peroxide used is not particularly limited, but one that decomposes at a temperature below the melting point of the low molecular weight polyolefin as a starting material is particularly preferable. preferable. For example, organic peroxide compounds or organic perester compounds are preferably used. Examples of the organic peroxide compound or organic perester compound include benzoyl peroxide, dichlorobenzoyl peroxide,
Dicumyl peroxide, di-t-butyl peroxide,
2,5-Dimethyldi (peroxybenzoate) hexyne-3,1,4-bis (t-butylperoxyisopropyl) benzene, lauroyl peroxide, t-butylperacetate, 2,5-dimethyl-2,5-di (t
-Butylperoxy) -hexyne-3,2,5-dimethyl-2,5-di (t-butylperoxy) -hexane,
t-butyl perbenzoate, t-butyl perphenyl acetate, t-butyl perisobutyrate, t-butyl per-s-octoate, t-butyl perpivalate, cumyl perpivalate, t-butyl perdiethyl acetate, etc. It is preferably used. In addition to these organic peroxide compounds or organic perester compounds, azo compounds such as azobisisobutyronitrile and dimethylazoisobutyronitrile can also be used in the present invention.

The amount of the organic peroxide used is usually 0.5 to 20 mol%, preferably 1 to 20% with respect to the unsaturated monomer.
It is 10 mol%.

When the graft copolymerization is carried out using an organic solvent, examples of the organic solvent used include aromatic hydrocarbons such as benzene, toluene and xylene, and aliphatic hydrocarbons such as hexane, heptane, octane and decane. Hydrocarbons, cyclohexane, cyclohexene, alicyclic hydrocarbons such as methylcyclohexane, ethanol, aliphatic alcohols such as isopropyl alcohol, acetone, methyl isobutyl ketone, ketone solvents such as methyl ethyl ketone, trichloroethylene, dichloroethylene, Mention may be made of halogenated hydrocarbons such as chlorobenzene.
These organic solvents may be used alone or in combination of two or more. Among these, aromatic hydrocarbons are preferable, and alkyl group-substituted aromatic hydrocarbons are particularly preferable.

In the method of the present invention, a modified low molecular weight polyolefin can be produced by graft copolymerizing an unsaturated monomer with a low molecular weight polyolefin as described above, but the graft copolymerization reaction is insufficient. In this case, the unreacted unsaturated monomer can be removed from the resulting reaction mixture by extraction with a suitable solvent or heating under reduced pressure, if necessary.

The modified low molecular weight polyolefin obtained by the method of the present invention has high hydrophilicity and is suitable for use as an emulsion. Furthermore, dispersion aids such as pigments, floor polish, car wax, fiber treatment agents,
It is also suitably used as a toner release agent. In addition, the modified low molecular weight polyolefin has remarkably improved conductivity as compared with the unmodified low molecular weight polyolefin.

[0033]

EXAMPLES Examples will be described below, but the present invention is not limited to these examples. In addition, the graft amount in the following is oxygen analysis (manufactured by HERAEUS).
CHN-O-RAPID) to determine the oxygen content,
It was calculated.

(Example 1) Low-molecular-weight polyethylene ([η]: 0.04) obtained by polymerization using a Ziegler catalyst.
15 dl / g) 600 g, internal volume 20 equipped with a stirrer
It was placed in a 0 ml glass reactor and heated to 160 ° C. to melt it. Further, nitrogen gas was blown from the bottom of the reactor at a flow rate of 40 l / hr to replace the inside of the reactor with nitrogen. Next, 150 g of 2-hydroxypropyl acrylate and 8.0 g of di-t-butyl peroxide were added dropwise over 2 hours while maintaining the temperature at 160 ° C. After completion of the dropping, the post-reaction was carried out for another hour to complete the reaction. Further, the unreacted compound was removed by stirring while heating at 160 ° C. for 2 hours under a reduced pressure of 100 mmHg to obtain a modified low molecular weight polyethylene. The grafted amount of 2-hydroxypropyl acrylate of the obtained modified low-molecular-weight polyethylene was 19% by weight.

The modified low molecular weight polyethylene 100 obtained
g, potassium hydroxide 3 g, a surfactant (manufactured by Kao Corporation,
Emulgen 220) 25 g, antifoaming agent (manufactured by Toshiba Silicone Co., Ltd., TSA-772) 1.0 g, and water 1
02 g was put into a 1 liter autoclave equipped with a stirring blade, heated to 140 ° C., and stirred. After stirring for 30 minutes, 273 g of boiling water was added, and stirring was continued at 140 ° C. for 20 minutes. Then, the temperature was returned to room temperature, and the particle size of the obtained emulsion was measured and found to be 0.11 μm. In addition, the emulsion was passed through a 100-mesh wire mesh, the amount of the non-emulsified product was measured, and the ratio of the non-emulsified product to the solid content of the emulsion was evaluated and evaluated according to the following criteria. A: Less than 0.1% by weight of unemulsified product X: More than 0.1% by weight of unemulsified product As a result, it was found that good emulsifying property was exhibited. Also,
The intrinsic viscosity [η], the softening point, the melting point and the density were measured, and the penetration hardness was measured according to JIS K2207 as an index of mechanical strength. The results are shown in Table 1.

(Example 2) Low-molecular-weight polyethylene ([η]: 0.04) obtained by polymerization using a Ziegler catalyst.
Using 39 g of (39 dl / g) as a raw material, the same reactor as in Example 1 was used to heat and melt at 170 ° C., and nitrogen substitution was performed. Then, while maintaining the temperature, 200 g of 2-hydroxyethyl methacrylate and 11 g of di-t-butyl peroxide were added dropwise over 2 hours. Further, post-reaction was carried out in the same manner as in Example 1 to remove unreacted compounds to obtain modified low molecular weight polyethylene. The amount of grafted 2-hydroxyethyl methacrylate of the obtained modified low molecular weight polyethylene was 23.8% by weight. Also, in the same manner as in Example 1, evaluation of emulsification property, intrinsic viscosity [η], softening point, melting point, density and penetration hardness were measured. The results are shown in Table 1.
Shown in.

Example 3 A low molecular weight propylene / ethylene copolymer obtained by thermal decomposition of a propylene / ethylene copolymer ([η]: 1.6 dl / g, propylene content 97 mol%) at 400 ° C. ([Η]: 0.2 dl / g) 600
g as a raw material, the same reactor as in Example 1 was used,
It was heated and melted at 180 ° C. and subjected to nitrogen substitution. Then
While maintaining the temperature, 50 g of 2-hydroxypropyl acrylate and 2.7 g of di-t-butyl peroxide were added dropwise over 2 hours. Further, post-reaction was carried out in the same manner as in Example 1 to remove unreacted compounds to obtain a modified low molecular weight propylene / ethylene copolymer. The graft amount of 2-hydroxypropyl acrylate of the resulting modified low-molecular-weight propylene / ethylene copolymer was 5.5% by weight. Also, in the same manner as in Example 1, evaluation of emulsification property, intrinsic viscosity [η], softening point, melting point, density and penetration hardness were measured. The results are shown in Table 1.

(Example 4) Low molecular weight ethylene obtained by thermally decomposing an ethylene / 1-butene copolymer ([η]: 1.5 dl / g, ethylene content: 90 mol%) at 420 ° C. 1-butene copolymer ([η]: 0.3 dl / g) 60
A modified low molecular weight ethylene / 1-butene copolymer was obtained by performing the same reaction as in Example 3 except that 0 g was used as a raw material. The grafted amount of 2-hydroxypropyl acrylate of the obtained modified low molecular weight ethylene / 1-butene copolymer was 6.1% by weight. Also, in the same manner as in Example 1, evaluation of emulsification property, intrinsic viscosity [η], softening point, melting point, density and penetration hardness were measured. The results are shown in Table 1.

(Example 5) Propylene / 1-butene copolymer ([η]: 2.0 dl / g, propylene content: 8)
0 mol%) was thermally decomposed at 380 ° C. to obtain a low molecular weight propylene / 1-butene copolymer ([η]: 0.1 dl /
g) 600 g as a raw material and 2 as an unsaturated monomer
A modified low molecular weight propylene / 1-butene copolymer was obtained by performing a graft copolymerization reaction in the same manner as in Example 1 except that -hydroxyethyl methacrylate was used. The grafted amount of 2-hydroxyethyl methacrylate of the obtained modified low molecular weight propylene / 1-butene copolymer was 18% by weight. Further, as in Example 1, evaluation of emulsification,
The intrinsic viscosity [η], softening point, melting point, density and penetration hardness were measured. The results are shown in Table 1.

Example 6 Example 6 was repeated except that low molecular weight polyethylene having an intrinsic viscosity [η]: 0.23 dl / g was used as the low molecular weight polyolefin and 2-hydroxyethyl methacrylate was used as the unsaturated monomer. A modified low molecular weight polyethylene was produced in the same manner as in 1. The amount of grafted 2-hydroxyethyl methacrylate of the obtained modified low molecular weight polyethylene was 10% by weight. In addition, the emulsifiability was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 1 As Example 1 except that low molecular weight polyethylene having an intrinsic viscosity [η]: 0.23 dl / g was used as the low molecular weight polyolefin and maleic anhydride was used as the unsaturated monomer. A modified low molecular weight polyethylene was produced in the same manner. The grafted amount of maleic anhydride on the obtained modified low-molecular-weight polyethylene was 4% by weight. Moreover, when the emulsification property was evaluated in the same manner as in Example 1, it was found that the ratio of the non-emulsified product that did not pass through the 100-mesh wire net was 50% by weight, and the emulsification property was poor. The results are summarized in Table 1.

Example 7 A low molecular weight polyolefin having an intrinsic viscosity [η]: 0.51 dl / g was used as the low molecular weight polyolefin, and 2-hydroxypropyl acrylate was used as the unsaturated monomer. A modified low molecular weight polyethylene was produced in the same manner as in 1. The graft amount of 2-hydroxypropyl acrylate of the obtained modified low-molecular-weight polyethylene was 10% by weight. In addition, the emulsifiability was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0043]

[Table 1]

[0044]

The modified low molecular weight polyolefin of the present invention is excellent in emulsifying property because it is obtained by selectively introducing only hydroxyl groups into the low molecular weight polyolefin. Further, according to the production method of the present invention, the modified low molecular weight polyolefin can be produced by a simple process without thickening during production.

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-62-148508 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08F 255/00-255/10

Claims (2)

(57) [Claims] 1. An intrinsic viscosity [η] of 0.01 to 0.7 dl /
a low molecular weight polyolefin g, of hydroxyl groups in the ester portion
Having a body (meth) Ri Na by polymerizing acrylic ester 1 to 40 wt% graft copolymer, the emulsion by adding water
Emulsion when passing through a 100 mesh wire mesh
When the ratio of the non-emulsion to the solid content of
A modified low molecular weight polyolefin. 2. The intrinsic viscosity [η] is 0.01 to 0.7 dl /
g of low molecular weight polyolefin and hydroxyl group in the ester part
3. A (meth) acrylic acid ester having a mere difference is graft-copolymerized in a molten state, and the viscosity is not increased during production.
The method for producing the modified low-molecular-weight polyolefin according to 1.