JPH01123811A - Production of graft-modified olefin copolymer - Google Patents

Abstract

PURPOSE:To obtain a copolymer used for improving the bondability and compatibility between polymers of different kinds, by graft-polymerizing a radical- polymerizable monomer with an olefin copolymer produced by a specified process. CONSTITUTION:An olefin copolymer is produced by the following step 1 and is subjected to the following step 2 to obtain the purpose graft-modified olefin copolymer. Step 1: an olefin copolymer is produced by copolymerizing at least either of ethylene and a 3-20C alpha-olefin with a dialkenylbenzene of the formula (wherein R<1> is methyl or H, R<2> is a 1-6C hydrocarbon residue, and n is 0 or 1) in the presence of a Ziegler-Natta catalyst. Step 2: a graft-modified olefin copolymer is produced by graft-polymerizing a radical-polymerizable monomer with the olefin copolymer obtained in step 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method for producing a graft-modified olefin copolymer. More specifically, the present invention focuses on the use of olefin polymers and copolymers that are added to improve the adhesion and compatibility between these different types of polymers when mixed with various other thermoplastic resins. The present invention relates to a method for producing a kraft-modified olefin copolymer for use as a kraft-modified olefin copolymer. Also,
The graft-modified olefin copolymer produced by the method of the present invention is non-polar and has no adhesion or affinity with polar substances. The extract has been given the miscibility, etc. of
It can be widely used alone or in combinations of polyolefins and other substances.

A method for producing a modified polyolefin by graft polymerizing a radically polymerizable monomer onto a polyolefin is a known "graft modification method" which has been tried many times since ancient times.

(Refer to JP-A-49-55790 and JP-A-50-32287.) However, in general, the radical grafting method does not have a sufficiently high grafting rate or grafting efficiency, and it is difficult to obtain a homopolymer of a 2-diyl-polymerizable monomer. Because it is easy to produce , specific polymerization methods have been devised to suppress it. (Unexamined Japanese Patent Publication No. 5
No. 2-32990, No. 52-50389, No. 52-5
(No. 0390, No. 52-86492) In addition, in the radical grafting method, a radical polymerization initiator such as an organic peroxide is often used, so molecular cleavage and cross-linking reactions of the backbone polymer to be grafted are prevented. It is difficult to efficiently obtain a graft-modified polyolefin having the desired properties, and improvements are desired in this respect as well.

The present inventors investigated a method for producing a graft-modified olefin copolymer in an attempt to improve the various problems of the above-mentioned radical grafting method, and as a result, they introduced a site with high radical grafting activity into an olefin polymer. As a result, the grafting reaction can proceed easily, and the grafting rate and The present invention was achieved by discovering that the grafting efficiency is improved or is effective in suppressing molecular scission and crosslinking reactions of the polyolefin backbone polymer.

That is, the present invention provides a method for producing a graft-modified olefin copolymer, which is characterized in that an olefin copolymer is produced in the following step 1, and the copolymer is used for polymerization in the following step 2. Out.

Step 1 One or more ethylene or α-olefins having 3 to 20 carbon atoms and the general formula (1), (where 11 is a methyl group or a hydrogen atom, H2 is a hydrocarbon residue having 1 to 6 carbon atoms, and n is Dialkenylbenzene represented by 0 or 1 respectively) and Ziegler
A step of copolymerizing in the presence of a Natsuta-type catalyst to produce an olefin copolymer, step 2 A step of graft polymerizing a radically polymerizable monomer to the olefin copolymer obtained in step 1 to produce a graft-modified olefin copolymer.

DETAILED DESCRIPTION OF THE INVENTION The method of the invention consists of step 1 followed by step 2.

Step 1: The Ziegler-Natsuta type catalyst used in Step 1 of the method of the present invention is a known catalyst, and includes transition metal compounds of Groups 1 to 2 of the periodic table (rides, alkoxides, acetylacetonates, etc.). ) and an organometallic compound of groups 1 to 2 of the periodic table.

Typical of these transition metal compounds are compounds of titanium, vanadium, and zirconium.
H(0R)a-n (where R is a hydrocarbon residue, n-
0~4), TiC20・mAtcta (m = O
~'A) and so-called supported titanium compounds in which these compounds are supported on magnesium chloride or the like. Further, these transition metal compounds may be modified with known electron-donating compounds (esters, ethers, amines, etc.).

Examples of organometallic compounds of Groups ① to ① of the periodic table include lithium, sodium, magnesium, aluminum, and other organometallic compounds having at least one carbon-metal bond, with the general formula RLi1RPMgX2-p, At
RqX3-q (R is an aliphatic, alicyclic or aromatic hydrocarbon residue having up to 20 carbon atoms, p is 1 or 2, qid1
~3).

Specifically, ethyllithium, n-propyllithium,
Inpropyl lithium, n-butyl lithium, 5eC-
Butyllithium, tert-butyllithium, n-decyllithium, phenyllithium, benzyllithium, l
-Naphthyllithium, p-tolyllium, cyclohexyllithium, α-methylstyryllithium, sodium naphthalene, ethylmagnesium chloride, butylmagnesium chloride, dibutylmagnesium, triethylaluminum, triimbutylaluminum, trihexylaluminum, diethylaluminum chloride, cyinobutyl Examples include aluminum chloride and diisobutylaluminum hydride.

These organometallic compounds can also be used in combination with known electron-donating compounds to form a Ziegler-Natsuta type catalyst in combination with a transition metal compound.

The ratio of the organic metal compound to the transition metal compound used is not particularly limited, but it is generally used within a range of 0.5 to 500 (molar ratio).

The copolymerization reaction of step 1 is carried out in the presence of the Ziegler-Natsuta type medium thus formed, and the ethylene or α-olefin having 3 to 20 carbon atoms used at this time is
Ethylene, propylene, fu.

ten-1, pentene-1,3-methylpentene-1, hexene-1,4-methylpentene-1,3-ethylbutene-1, heptene-1,4r4-cymedelpentene-1
, 3,3-dimethylbutene-1, etc. Among these, ethylene or an α-olefin having 3 to 10 carbon atoms is preferred, and ethylene or propylene is particularly preferred. Incidentally, these monomers can be used in combination. These monomers may also be supplemented with small amounts, especially up to 10 wt. of dienes (e.g. butadiene, 4-methylhexadiene,
5-methylhexadiene, etc.) may also be included.

These dialkenylbenzenes used in the present invention are represented by the following general formula (1), and may be any isomer such as 〇-isomer, m-isomer, or p-isomer, or may be a mixture. Various derivatives in which the benzene ring is substituted with another hydrocarbon residue may also be used.

(However, R1 represents a methyl group or a hydrogen atom, B2 represents a hydrocarbon residue having 1 to 6 carbon atoms, and n represents 0 or l, respectively.) Specific examples include divinylbenzene and inogropenylstyrene. , divinyltoluene, divinylnaphthalene, etc. Commercially available crude divinylpenzene, ethylvinylbenzene, diethylbenzene, etc. are also included, but these can be used in one process without separate separation.

The copolymerization of one or more of the above-mentioned ethylene or α-olefins having 3 to 20 carbon atoms and the dialkenylbenzene represented by the general formula CI) can be carried out under polymerization conditions using a conventional Ziegler-Natsuta type catalyst.

In this case, in so-called melting reactions using inert diluents, hexane, heptane, cyclohexane, benzene,
Toluene, xylene fk, etc. (D charcoal ('C hydrogen solvent) can be used. The polymerization temperature is 0 to 120°C, preferably 2
It can be carried out at temperatures between 0 and 90°C.

The polymerization pressure can be selected within a wide range and ranges from atmospheric pressure to about 50 #/d1, preferably 1 to 30 kg/I:II, are used.

In the present invention, step 1 is carried out under known polymerization conditions as described above.
The polymerization form of the α-olefin may be not only a homopolymerization form of these monomers, but also a random polymerization form using a mixture of these monomers, or a block polymerization form.

The polymerization form of dialkenylbenzene copolymerized with these monomers may be either random polymerization form or block polymerization form, but random polymerization form is preferable.

Furthermore, dialkenylbenzene (D jl Ka0.001 to
It is important that the amount is 10% by weight, preferably 0.05 to 5% by weight. If this content is too high, gelation of the polymer will easily occur, and if this content is too low, the graft polymerization in step 2 will not be carried out effectively.

The content of this dialkenylbenzene in the reflex copolymer is determined by the type of Ziegler-Natsuta catalyst used, the type and degree of crushing of ethylene or α-olefin, the amount of dialkenylbenzene supplied, the rate of supply, the polymerization temperature, the polymerization Controlled by time etc.

Moreover, the molecular tFi of the obtained olefin copolymer can be controlled by known methods such as addition of hydrogen.

The olefin copolymer thus obtained can be used as it is in the graft polymerization in Step 2, but preferably, the one obtained by stopping the copolymerization reaction in Step 1 is
More preferably, the obtained olefin copolymer is used in step 2 after being washed with an inert hydrocarbon solvent such as hexane, heptane, xylene, or decalin.

The radically polymerizable monomer used in step 2 is as follows:
Well-known materials can be used, and specific examples include the following. Styrene, α-methylstyrene, p-methylstyrene, t-)methylstyrene, allylbenzene, butadiene, imbrene, chloroprene, vinyl heptatide, vinyl chloride, vinyl bromide, vinylidene heptafluoride, vinylidene chloride, vinylidene bromide , tetrafluoroethylene, trifluoroethylene, chlorotrifluoroethylene, dichlorodifluoroethylene, vinyl acetate, vinyl propionate, methyl acrylate, ethyl acrylate, butyl acrylate, octyl acrylate, stearyl acrylate, methacrylic acid Methyl, ethyl methacrylate, butyl methacrylate, octyl methacrylate, stearyl methacrylate, methacrylic acid, itaconic acid, methylene glutaric acid,
Itaconic anhydride, mesol vinyl ketone, phenyl vinyl ketone, ethyl vinyl ketone, methyl inferrobenyl ketone, meso b vinyl ether, ethyl vinyl ether, phenyl vinyl ether, hinylte x-thyl, acrylonitrile, acrylamide, acryldimethylamide, dimethylaminoethyl methacrylate, 2-hydroxyethyl acrylate, glycerin methacrylate,
Glycidyl acrylate, glycidyl methacrylate, allyl acrylate, allyl methacrylate, ethylene glycol
IJ rate, divinyl ether, N-vinylpyrrolidone, N-vinylimidazole, ethylmaleimide, N-vinyl 7-talimide, vinylpyridine, N-vinylcarbazole, N-vinyl-N-methylacetamide, N,N -dimethylaminoether acrylate, t-butylacrylamide, methacrylamide, t-butylaminoethyl methacrylate, vinyl sulfide, trimethoxyvinylsilane, triethoxyvinylsilane, γ
- methacrylglobiltrimethoxysilane, vinyltrichlorosilane, diphenylmethylvinylsilane, etc.

These radically polymerizable monomers can be used alone or in combination of two or more.

Well-known sources of radicals are used, including heat, radical initiator catalysts, ultraviolet rays, and radiation.

The radical initiator catalyst is so-called benzoyl peroxide,
Peroxides such as tertiary butyl peroxide, tertiary butyl hydroxyperoxide, potassium persulfide, azo compounds such as α,cr'-azobisinbutyronitrile, or redox compounds such as hydrogen peroxide and ferrous salts. It is a catalyst.

These radical generating sources are appropriately selected in relation to the type of monomer and polymerization method. The radical polymerization method can be carried out by a commonly used bulk polymerization method, solution combination method, suspension polymerization method, or emulsion polymerization method.

The temperature of the radical graft polymerization reaction is usually 50 to 300℃.
C, preferably in the range of 70 to 200 C, and the polymerization time is in the range of 10 minutes to 30 hours, preferably 10 minutes to 10 hours.

The graft polymerization in step 2 is carried out as described above, but the type of radically polymerizable monomer in the target graft-modified olefin copolymer, the graft volume (weight composition)
, the molecular weight of the graft chain, etc. can be appropriately selected depending on the purpose of the desired graft-modified olefin copolymer. For example, a copolymer of ethylene and divinylbenzene, a copolymer of propylene and divinylbenzene, or ethylene,
In the case where the copolymer of propylene and divinylbenzene is the olefin copolymer obtained in step 1, the content of the radically polymerizable monomer in the graft-modified olefin copolymer is 5 to 90% by weight. is preferable.

Effects of the Invention According to the method of the present invention, unlike known radical graft modification methods of polyolefins that do not use dialkenylbenzene as one of the copolymerization components, the molecular chain scission and crosslinking reactions of the olefin copolymer as the backbone polymer are performed. It becomes possible to efficiently set any graft monomer and graft a to perform graft modification while suppressing the above.

(The resulting graft-modified olefin copolymer has a gel fraction of 5% or less (bromine is added to the unreacted alkenyl groups that were not used in the grafting reaction in advance, and then Soxhlet extraction is performed using xylene. The remaining amount is the gel content), and it has a wide range of properties due to the fluorograft-modified olefin copolymer.
For example, it can be used as a compatibilizer for mixtures of polyolefins and various resins, or as adhesives between polyolefins and various resins, and can also be used to improve adhesion, dyeability, printability, miscibility with other polar resins, etc. It can be used in a wide range of applications, including as an olefin copolymer.

Examples Example 1 (Step 1: Copolymerization of propylene and divinylbenzene) In a stainless steel autoclave with an internal volume of 1 liter and equipped with a stirring and solidity control device, vacuum-propylene displacement was repeated several times, followed by thorough dehydration and dehydration. 500 ml of deoxygenated n-hebutane, divinylbenzene (manufactured by Tokyo Kasei Co., Ltd., simple distillation of a mixture of m-integrated and p-integrated divinylbenzene, divinylbenzene content TS 3%) 20-,
Diethylaluminium chloride 23419. Titanium trichloride (manufactured by Toyo Stouffer Co., Ltd., rTTA-12J) Z
o.

ηCAt/Seal=3 (molar ratio)] were introduced in this order, and 450 d of hydrogen was added to start copolymerization of propylene and divinylbenzene. Copolymerization conditions are propylene pressure cuff #/
e! IIG, 65°C, 3 hours.

After the copolymerization was completed, the remaining monomer was purged, and the polymer slurry was sent door to door to obtain 108.8f of copolymer powder polymer (catalytic activity 3,500f copolymer/? sealed, MFR = 5
．． 0 t710 min, stereoregularity by boiling hebutane extraction method is 98.1%). The content of copolymerized divinylbenzene in this copolymer was measured by ultraviolet spectroscopy and was found to be 0.40% by weight.

(Step 2 Graft polymerization of butyl diacrylate) Internal volume 5
Transfer the copolymer obtained in step 1 above to a 0 m flask. After vacuum evacuation, add butyl acrylate 5 under nitrogen gas atmosphere.
．． After adding Om, thermal graft polymerization of butyl acrylate was carried out at 110° C. for 4 hours.

After the polymerization was completed, the present polymer was added to a large excess of hebutane, washed and dried to obtain butyl acrylate graft-modified polypropylene exhibiting the infrared absorption spectrum shown in FIG.

In FIG. 1, a spectrum peculiar to butyl acrylate grafts is observed around 1730 cm-''.

Using about 1f of this graft, Soxhlet extraction was performed for 5 hours using methyl ethyl ketone (MEK) as the extraction solvent, and the MEK extracted insoluble matter was dried and the infrared absorption spectrum was similarly measured, as shown in Figure 2. Obtained data. In FIG. 2, a spectrum exactly the same as in FIG. 1 is observed, indicating that polybutyl acrylate is not a homopolymer but is grafted onto polypropylene.

One of the measures of grafting efficiency is the infrared absorption spectrum (Axy3oi'/AosocfIT after solvent extraction/
(AxnocrrT'/lu z6oti'') before solvent extraction was calculated to be 0.73.

(Here, A is the absorbance of each wave number.9.116
03 is an absorption spectrum specific to polypropylene. ) Comparative Example 1 Homopolymerization of propylene was carried out under exactly the same conditions as in Example 1, except that the amount of divinylbenzene used in the polymerization in Step 10 of Example 1 was changed to O, and polypropylene 205.2 was obtained.
f was obtained (catalytic activity 6600 fpp/P sealed, MFR=*
s, sr/lo min).

Graft polymerization of butyl acrylate was attempted under the same conditions and method as in Step 2 of Example 1, except that this polymer 1t was used. could only be detected as a trace, and the desired graft-modified polypropylene could not be obtained.

Example 2 (Step I: Copolymerization of ethylene/furopylene/divinylbenzene) After repeating xq-propylene substitution several times in a stainless steel autoclave with an internal volume of 1 liter equipped with a stirring and temperature control device, the mixture was thoroughly dehydrated. and deoxygenated n-
Hebutane 500tj, divinylbenzene (same as used in Example 1) 1mS n-butyllithium 3
．． 86 mmol, titanium tetrachloride 1.97 mmol (Li
/Ti = 1.9 e (molar ratio)] were introduced in this order to form a Ziegler-Natsuta type catalyst.

After adding 1500jIj of hydrogen to the removed grains, a mixed gas of ethylene and propylene was continuously added at a rate of 13t/each.
Copolymerization of (ethylene/propylene/divinylbenzene) was carried out by introducing the mixture into an autoclave at a rate and quantity ratio of 33 t/hour.

The copolymerization temperature and time at this time were 25° C. and 3 hours, respectively (constant rate feed polymerization method for α-olefins).

After the copolymerization is completed, the entire contents of the autoclave are subjected to steam stripping 49. An olefin copolymer of Of was obtained.

The ethylene/propylene weight composition ratio of this copolymer was analyzed by infrared spectroscopy and was found to be 59/41. Further, the content of polymerized divinylbenzene was analyzed by ultraviolet spectroscopy and was found to be 0.17%.

(Step 2: Graft polymerization of methyl methacrylate) Put 1 t of the olefin copolymer obtained in Step 1 above into a flask with an internal volume of 50 d, and after evacuation, add 3 d of toluene and 5 d of methyl methacrylate under a nitrogen gas atmosphere at 80°C.
Thermal graft polymerization of methyl methacrylate was carried out for 4 hours.

After the polymerization was completed, the graft polymer was washed with a7tone at room temperature and dried to obtain a methyl methacrylate graft-modified olefin copolymer exhibiting the infrared absorption spectrum shown in FIG.

In FIG. 4, a spectrum peculiar to Medel methacrylate grafts is observed around 1720 to 1730a++.

Noxley extraction with MEK was performed for 5 hours using this graft body 1f, and the MEK-extracted insoluble matter was dried, and the infrared absorption spectrum was similarly measured, and the data shown in FIG. 5 was obtained. A unique absorption spectrum of polymethyl methacrylate is also observed in FIG. 5, indicating that polymethyl methacrylate is grafted onto the olefin copolymer obtained in step 1.

As a measure of grafting efficiency, the infrared spectrum was measured after solvent extraction.
2-convex tzocm;'') before solvent extraction was calculated and found to be 0.44.

(Here, 720 cm"" is an absorption spectrum specific to polyethylene.) Example 3 (Step 1: Copolymerization of ethylene/furopylene/divinylbenzene) Except for changing the amount of divinylbenzene used in Example 2 to 3.0 d. (ethylene/furopylene/divinylbenzene) copolymer 43 was prepared under exactly the same conditions and method as in Example 2.
．． 1 f was obtained.

The ethylene/propylene weight composition ratio of this copolymer is 66
/34, and the polymerized divinylbenzene content is 0.2
It was set at 6% by weight.

(Step 2: Graft polymerization of methyl methacrylate) Thermal graft polymerization exactly as in Step 2 of Example 2 was performed using the copolymer 1f obtained in Step 1 above.

FIGS. 6 and 7 show infrared absorption spectra before and after Soxhlet extraction using MEK, respectively. Moreover, the grafting efficiency defined in Example 2 was 0.60.

Example 4 (Step 2: Graft polymerization of styrene to polypropylene) To a flask with an internal volume of 11 J, 200 dl of distilled water and 6 ml of tertiary calcium phosphate were added. , 0.012 f of sodium dodecylbenzenesulfonate was added, and after stirring for 5 minutes, 0.25 f of styrene monomer 5011 benzoyl peroxide and 0.70 f of t-butyl peroxybivalate were added under a nitrogen gas atmosphere. , 50f of the propylene/divinylbenzene copolymer obtained in Step 1 of Example 1 was added. This was stirred at a speed of 200-250 rpm and heated to 50°C for 30 minutes.
Styrene graft polymerization was carried out at 75° C. for 2 hours and then at 90° C. for 3 hours.

After cooling, the contents were taken out and washed with a large excess of water to obtain the desired styrene craft modified polypropylene of 99.99% (styrene conversion rate of 99.8%).

Using this graft-modified polypropylene 10f, MEK
Soxhlet extraction was carried out for 5 hours, and the polystyrene content in the extracted insoluble matter was determined by infrared spectroscopy to be 20.5% by weight (grafting rate = 20.5
weight%).

Therefore, the grafting efficiency defined as [radically polymerizable heptad polymer (weight) not extracted with extraction solvent/total radically polymerizable monomer polymer (weight)) x 100 is 26
%Met.

Comparative Example 2 When the styrene graph) was synthesized using the method and conditions of Example 4, propylene homopolymer 5 obtained in Comparative Example 1 was used instead of using a copolymer of propylene and divinylbenzene.
This was done using 0F. As a result, graft copolymer 1
00F was obtained (styrene conversion rate 100%).

MEK of this graft copolymer was prepared in the same manner as in Example 4.
The polystyrene content in the extracted insoluble matter was determined to be 6.2% by weight. Therefore, the grafting efficiency defined in Example 4 was as low as 6.7%.

A comparison with Example 4 and Comparative Example 2 shows that polypropylene homopolymer is also graft-modified when a radical initiator such as an organic peroxide is used, but when the copolymer of propylene and divinylbenzene of the present invention is used. It can be seen that both the grafting rate and the grafting efficiency are significantly lower than that of the above.

[Brief explanation of the drawing]

1 and 2 are the IR spectra of the polymer obtained in Example 1, FIG. 3 is in Comparative Example 1, FIGS. 4 and 5 are in Example 2, and FIGS. 6 and 7 are in Example 3. FIG. Patent applicant: Mitsubishi Yuka Co., Ltd. Agent: Masahisa Hase Patent attorney: Patent attorney Takaya Yamamoto

Claims (1)

[Claims] (1) A method for producing a graft-modified olefin copolymer, which comprises producing an olefin copolymer in Step 1 below, and carrying out polymerization in Step 2 below using the copolymer. ￥Process 1￥ Ethylene or one or more α-olefins having 3 to 20 carbon atoms and general formula (I), ▲Mathematical formula, chemical formula, table, etc.▼(I) (However, R^1 is a methyl group or hydrogen atom, R^2 represents a hydrocarbon residue having 1 to 6 carbon atoms, and n represents 0 or 1, respectively) in the presence of a Ziegler-Natsuta type catalyst to form an olefin copolymer. Process of producing a polymer, ¥Step 2¥ A process of graft polymerizing a radically polymerizable monomer to the olefin copolymer obtained in Step 1 to produce a graft-modified olefin copolymer.