JPH0635513B2 - Method for producing epoxy group-grafted polyolefin copolymer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing an epoxy group-grafted polyolefin copolymer by mixing and reacting a specific vinyl copolymer and polyolefin.

More specifically, the present invention relates to a production method capable of easily and efficiently obtaining an epoxy group-grafted polyolefin by a radical reaction of a peroxy group in a specific vinyl-based copolymer without requiring a special polymerization step.

When the epoxy group-introduced polymer is mixed with inorganic filler, magnetic powder, aluminum powder, glass fiber, etc., improve the dispersibility and adhesiveness of them, and improve the adhesiveness with polar polymers and metallic materials. It becomes a useful polymer material.

(Prior Art) So-called epoxy group-grafted modified polyolefin such as polyethylene and polypropylene grafted with an epoxy group has conventionally been grafted with glycidyl methacrylate in the form of a monomer to perform surface modification of fibers, films, etc. It is used for imparting dyeability and adhesiveness, improving the dispersibility of polyamide or polyester, and improving the adhesiveness to metals.

In JP-B-45-30945, a polyolefin is grafted with glycidyl methacrylate in a solution with benzoyl peroxide to obtain a modified polyolefin having a polar group, which is added to a polyamide or polyester to improve the dispersibility.

Further, in JP-B-45-6430, an elastomer is grafted with glycidyl methacrylate, mixed with an alkyd resin, and used as a coating agent and an adhesive.

Further, in JP-A-52-98720, a polyolefin film is exposed to a discharge of 50 W under reduced pressure in an argon gas for 30 seconds to activate the surface of a substrate, which is dipped in a solution of glycidyl methacrylate to graft an epoxy group to improve dyeability. Is improving.

Further, in JP-A-52-132086, a modified polyolefin in which glycidyl methacrylate is grafted is laminated on iron or an iron-containing alloy to obtain a composition excellent in salt water peeling resistance.

Therefore, the conventional method for producing a modified epoxy group-grafted modified polyolefin is obtained by using a glycidyl acrylate or glycidyl methacrylate monomer and grafting it onto the polyolefin, or by adding the monomer to the polymerization step of the polyolefin and copolymerizing it. It was a method.

(Problems to be Solved by the Invention) Various methods as described above are known for introducing an epoxy group into a polyolefin, but a copolymerizable monomer containing all epoxy groups is used. It is introduced by polymerization or grafting reaction.

In the case of copolymerization, there is a problem in the reactivity between the monomers used, and the epoxy group-containing copolymerizable monomer undergoes polymerization during preheating, and the equipment and polymerization conditions must be strictly controlled. Nakatsuta. Further, in the production of a small amount and a large variety of products, the polymerization equipment becomes complicated and there is an economical problem.

When the epoxy group-containing copolymerizable monomer is grafted to the polyolefin, a homopolymer of the epoxy group-containing copolymer is easily formed, and the grafting efficiency does not always reach a value that satisfies the requirement. It was necessary. Further, the solution method in which polyolefin is diluted or dispersed in a solvent and grafted with an epoxy group-containing copolymerizable monomer requires a large amount of solvent, and when the graft product is taken out, a lot of energy such as desolvation and drying is required. did. In the bulk method, the solubility of polyolefin in the epoxy group-containing copolymerizable monomer limits the performance of the grafted polyolefin product, and when the epoxy group-containing copolymer is used as a molding material, it is further pelletized. Alternatively, a grinding process was necessary. In the impregnation method, it was not easy to set the particle size of the polyolefin and the optimum conditions of the impregnation process, and the performance of the product was restricted.

As described above, there are two problems in the conventional grafting method, that a polymerization step is always necessary, and that there are many homopolymers and unreacted monomers, and the grafting rate is considerably low. To be

(Means for Solving Problems) As a result of long-term research for solving the above-mentioned conventional problems, the present inventors have found that a vinyl-based copolymer containing a peroxy group and an epoxy group is used. The present invention was completed by confirming that an epoxy group-grafted polyolefin can be easily and efficiently obtained by radical reaction of a polyolefin with a peroxy group.

The present invention is a process for producing an epoxy group-grafted polyolefin, which comprises reacting a vinyl copolymer containing a peroxy group and an epoxy group with polyolefin to graft the copolymer onto the polyolefin.

The present invention is characterized by using a vinyl-based copolymer containing a peroxy group and an epoxy group. First, an example of a method for producing this copolymer will be shown. That is, it is obtained by a copolymerization reaction of a copolymer monomer containing an unsaturated peroxycarbonate and an epoxy group with an acrylic ester and / or a styrene-based monomer.

As the unsaturated peroxycarbonate used in this copolymerization reaction, for example, the following general formula (I) (Wherein R ₁ and R ₂ represent a hydrogen atom or a methyl group, and
₃ represents a linear alkyl group having 1 to 9 carbon atoms, a branched alkyl group, a phenyl group or an alkyl-substituted phenyl group having 1 to 3 carbon atoms. ). Specifically, t
-Butylperoxyacryloyloxyethyl carbonate, t-butylperoxymethacryloyloxyethyl carbonate, t-amylperoxyacryloyloxyethyl carbonate, t-amylperoxymethacryloyloxyethyl carbonate, t-hexylperoxyacryloyloxyethyl carbonate, t -Hexylperoxymethacryloyloxyethyl carbonate, cumylperoxyacryloyloxyethyl carbonate, cumylperoxymethacryloyloxyethyl carbonate,
Isopropyl cumyl peroxyacryloyloxyethyl carbonate, isopropyl cumyl peroxymethacryloyloxyethyl carbonate, t-butyl peroxyacryloyloxy isopropyl carbonate, t-butyl peroxymethacryloyloxy isopropyl carbonate, t-amyl peroxyacryloyloxy isopropyl carbonate, Examples include t-amyl peroxymethacryloyloxy isopropyl carbonate, cumyl peroxyacryloyloxy isopropyl carbonate and cumyl peroxymethacryloyloxy isocarbonate.

Further, as the copolymerizable monomer containing an epoxy group, for example, the following general formula (II) (In the formula, R ₄ represents a hydrogen atom or a methyl group). This monomer is specifically glycidyl acrylate and glycidyl methacrylate.

Further, as the acrylic ester, for example, the following general formula
(III) (In the formula, R ₅ represents a hydrogen atom or a methyl group. R ₆ represents a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group). Specifically, for example, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate,
2-hydroxyethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate,
Examples thereof include 2-ethylhexyl methacrylate and 2-hydroxyethyl methacrylate, and examples of the styrene-based monomer include styrene, α-methylstyrene, t-butylstyrene and chlorostyrene.

The above acrylic ester and styrene-based monomer may be used either individually or in combination of two or more, and may be used in combination.

And the amount of them is 0.001 to 10 parts by weight of the unsaturated peroxycarbonate represented by the general formula (I), when the total parts by weight involved in the production of the copolymer is 100 parts by weight, and the general formula (II 1 to 30 parts by weight of the epoxy group-containing copolymer represented by the formula (1), and the balance is an acrylic ester and / or a styrene monomer.

If the unsaturated peroxycarbonate is less than 0.001 part by weight, the ratio of the peroxy groups contained in the vinyl-based copolymer is too small and a useful grafting reaction cannot be expected.
If it exceeds 10 parts by weight, there are too many peroxy groups in the vinyl-based copolymer, which may cause a rapid decomposition during handling or heating.

When the amount of the epoxy group-containing copolymer is less than 1 part by weight,
If the amount of epoxy groups in the epoxy group-grafted polyolefin copolymer, which is the final product, is too small, and if it exceeds 30 parts by weight, the hydration ring-opening reaction will increase and storage stability will become a problem.

In this way, a specific vinyl-based copolymer containing a peroxy group and an epoxy group can be obtained.

The specific vinyl copolymer obtained can measure the content of unsaturated peroxycarbonate pendant from the active oxygen content by the usual iodometry method, and its epoxy equivalent by the titration method with the usual hydrogen bromide-acetic acid solution. The content of the copolymerizable monomer containing the pendant epoxy group can be measured.

The polyolefin targeted by the present invention is, for example, an ethylene-vinyl acetate polymer (EVA) having a vinyl acetate content of 5 to 50 parts by weight, ethylene-propylene rubber (EPR), 1,4.
-Ethylene-propylene terpolymer (EPDM) containing non-conjugated dienes such as hexadiene, dicyclopentadiene and ethylidene norbornene as the third component, medium and high density polyethylene (MDPE, HDPE), low density polyethylene (LDP)
E) and polypropylene (PP).

According to the method of the present invention, the specific vinyl copolymer is mixed with polyolefin in the molding machine or in the kneading machine and melted by heating, or by blending by roll kneading, and the vinyl copolymer is mixed with a peroxy group by heat pressing. An epoxy group-grafted polyolefin copolymer can be produced by efficiently grafting to polyolefin by a radical reaction.

The grafting can be carried out not only by the heating and melting method and the roll kneading method but also by the solution method, the block method and the impregnation method.

The amount of the specific vinyl-based copolymer to be used with respect to the polyolefin varies depending on the purpose and application, but it is usually
90 to 0.1 parts by weight is preferable to 10 to 99.9 parts by weight, and more preferably 50 to 1 parts by weight to 50 to 99 parts by weight of polyolefin. If the proportion of the specific vinyl copolymer exceeds 90 parts by weight, there is a chance of contact due to the mismatch of the numerical balance between the vinyl copolymer radical generated by the cleavage of the peroxy bond and the polyolefin radical generated by the hydrogen abstraction reaction. As a result, the graft efficiency decreases. Further, if the proportion of the specific vinyl-based copolymer is less than 0.1 part by weight, the effect of epoxy group grafting may not be exhibited, which is not preferable.

In the present invention, when the specific vinyl copolymer is grafted to polyolefin, various peroxides may be used together for the purpose of efficiently producing the polyolefin radical. As the peroxide,
For example, benzoyl peroxide, dicumyl peroxide, 1,1-bis (t-butylperoxy) 3,3,5
-Trimethylcyclohexane, t-butylcumyl peroxide, di-t-butyl peroxide, α, α'-bis (t-butylperoxyisopropyl) benzene, 2,
Examples include 5-dimethyl-2,5-di (t-butylperoxy) hexane and 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3. The amount used is in the range usually used, that is, in the range of 0.01 to 5% by weight based on the total amount of the specific vinyl copolymer and the polyolefin.

The grafting efficiency can be determined by fractionally precipitating the obtained epoxy group-grafted polyolefin copolymer.

The grafting in the present invention will be described with an example of a heating and melting method, which is one of the main methods. That is, when a specific vinyl copolymer is heated and melted with polyolefin (for example, at 200 ° C.), first, the peroxide bond in the vinyl copolymer is cleaved, and the generated radical pulls hydrogen from the polyolefin. An epoxy group-grafted polyolefin copolymer is obtained by producing a polyolefin radical and recombining the radical with the radical in the vinyl copolymer.

(Effect of the invention) The feature of the present invention is that a graft body can be obtained only by heating and melting powdery, bead-shaped, block-shaped or rubber-shaped polyolefin and a specific vinyl copolymer in a molding machine or a kneading machine. Therefore, the method is simple and suitable for industrial production without a special polymerization step unlike the conventional method. Since it does not include a polymerization step, there is no need for equipment required for each step of handling a monomer, polymerization and drying, and grafting can be easily carried out by simply using equipment such as a conventional molding machine. Further, the grafting method in the present invention is hardly affected by fluctuations in conditions such as reaction temperature, reaction time and addition amount,
It is possible to achieve high grafting efficiency with good reproducibility, which is not possible with conventional methods.

Therefore, the grafting method according to the present invention is not only a method for producing an improved polyolefin, which is an improvement of the drawbacks of polyolefin, but can be grafted to a polymer substrate having any active oxygen which is easily dehydrogenated and thus has improved adhesion. It is useful for application fields such as inorganic fillers, pigments, and metal dispersibility.

(Example) Hereinafter, the present invention will be described with reference to Reference Examples, Examples and Comparative Examples.

Reference Example 1 (Production of Specific Vinyl Copolymer by Suspension Polymerization) 4 in a four-necked flask with an internal volume of 1 equipped with a stirrer, a thermometer, a Dimroth condenser, a nitrogen gas introduction tube and a dropping funnel.
00 ml of 0.2% by weight of polyvinyl alcohol (degree of hydrolysis 8
9%) aqueous solution was added and the temperature was adjusted to 60 ° C. Separately styrene 1
80 g, t-butylperoxymethacryloyloxyethyl carbonate (purity 96%) 3.1 g, glycidyl methacrylate (purity 97%) 17.5 g, and diisopropyl peroxydicarbonate (purity 99%) 2.0 as a polymerization initiator
A mixed solution of g was prepared, and this was added dropwise at 60 ° C. for 10 minutes while stirring while flowing a nitrogen gas. Subsequently, stirring was continued for 8 hours, and after completion of the reaction, another drying was performed to obtain 188.5 g of a transparent bead-like polymer. A portion of this was repeatedly dissolved and reprecipitated in a toluene-methanol system and dried under reduced pressure to measure the amount of active oxygen by iodometry. As a result, the content of pendant t-butylperoxymethacryloyloxyethyl carbonate was 1.46 wt. %, And the content of epoxy groups pendant from the titration method with a hydrogen bromide-acetic acid solution was 8.02% by weight. Also, from the measurement of infrared absorption spectrum, the absorption of the peroxycarbonate group was 17
To 90cm ^-1, absorption of epoxy group was observed to 1250cm ^-1. From this, it was confirmed to be a copolymer containing a peroxy group and an epoxy group.

Reference Example 2 (Production of Specific Vinyl Copolymer by Suspension Polymerization) Methyl methacrylate 85 g, n-butyl acrylate 70
g, t-butylperoxyacryloyloxyethyl carbonate (purity 95%) 10.6 g, glycidyl methacrylate (purity 97%) 36 g, and benzoyl peroxide 0.1 g as a polymerization initiator were added, and the reaction was carried out at 80 ° C for 6 hours. The same procedure as in Reference Example 1 was carried out to obtain 185 g of a polymer.
Further, a part of this was purified, and as a result of measurement by the same measurement method as in Reference Example 1, the pendant t-butylperoxyacryloyloxyethyl carbonate content was 4.81% by weight,
The content of pendant glycidyl methacrylate is 1
It was confirmed to be 6.5% by weight and the copolymer was a copolymer containing a peroxy group and an epoxy group.

Reference Example 3 (Production of Specific Vinyl Copolymer by Suspension Polymerization) Styrene 90 g, 2-ethylhexyl acrylate 20 g,
Methyl methacrylate 32g, t-hexyl peroxymethacryloyloxyethyl carbonate (purity 92%) 8.7
g, 50 g of glycidyl acrylate (purity 95%), and 2.0 g of diisopropyl peroxydicarbonate (purity 99%) as a polymerization initiator were added, and the reaction was carried out at 60 ° C. for 8 hours. 185 g were obtained. Further, a part of this was purified and measured by the same measuring method as in Reference Example 1, and as a result, the content of pendant t-hexylperoxymethacryloyloxyethyl carbonate was 3.6% by weight.
It was confirmed that the content of pendant glycidyl methacrylate was 22.9% by weight, and the copolymer was a copolymer containing a peroxy group and an epoxy group.

Reference Example 4 (Production of Peroxy- and Epoxy-Group-Containing Vinyl Copolymer by Solution Polymerization Method) As a solvent in a four-necked flask having an inner volume of 500 ml equipped with a stirrer, a thermometer, a Dimroth condenser, and a nitrogen gas introduction tube. Butyl cellosolve 200 g, methyl methacrylate 65 g, glycidyl methacrylate (purity 97%) 10.3 g, α-cumylperoxymethacryloyloxyethyl carbonate (purity 87%) 5.7 g, 2-hydroxymethacrylate 20
After adding g and adjusting the temperature to 80 ° C., 1.0 g of benzoyl peroxide (purity 99%) was added as a polymerization initiator, and the reaction was carried out for 6 hours while stirring under a nitrogen gas flow. Then, the reaction solution was added dropwise to 1.5 diethyl ether to cause precipitation, which was dried under reduced pressure to obtain 93 g of a white powder. A part of this white powder was further purified by butyl cellosolve-diethyl ether, and the result of measurement by the same measurement method as in Reference Example 1,
The content of pendant α-cumyl peroxymethacryloyloxyethyl carbonate was 4.7% by weight, the content of pendant glycidyl methacrylate was 9.6% by weight, and the copolymer was a copolymer containing peroxy groups and epoxy groups. It was confirmed that they were united.

Reference Example 5 (Production of vinyl copolymer containing peroxy group and epoxy group by suspension polymerization method) In Reference Example 1, t-butylperoxymethacryloyloxyethyl carbonate was used instead of t-butylperoxymethacryloyloxyisopropyl carbonate. Other than the above, the procedures and processes according to Reference Example 1 were carried out, and the yield was 175
g product was obtained. The content of pendant t-butylperoxymethacryloyloxyisopropyl carbonate was 1.40% by weight, and the content of glycidyl methacrylate was 8.0% by weight.

Reference Example 6 (Production of vinyl-based copolymer containing only epoxy group by suspension polymerization method) Operation and treatment according to Reference Example 2 except that t-butylperoxyacryloyloxyethyl carbonate was not used in Reference Example 2. The product was obtained in a yield of 180 g. The content of pendant glycidyl methacrylate was 14.0% by weight.

Example 1 Ethylene-vinyl acetate copolymer (EVA, manufactured by Steel Chemical Industry Co., Ltd., Flowback K2010 vinyl acetate content 25% by weight, melt index 3 g / 10 minutes, density 0.95 g / cm ² ) 10
0 parts by weight and the vinyl-based copolymer 3 produced in Reference Example 1
Using a Brabender mixer, 0 part by weight was kneaded at 180 ° C. for 5 minutes to obtain a resin composition.

This composition was fractionally precipitated and the grafting efficiency was calculated.
That is, the composition is dissolved in a predetermined amount of benzene and poured into 50 times the volume (volume) of acetone, and the unreacted vinyl-based copolymer that has not been grafted is dissolved in acetone. The separated precipitate separated from EVA was dried under reduced pressure, and the weight was measured to calculate the graft efficiency. The reaction conditions and the reaction results are shown in Table 1.

Example 2 The graft efficiency was calculated by performing the same operations and treatments as in Example 1 except that the kneading temperature of 180 ° C. was changed to 220 ° C. The reaction conditions and the reaction results are shown in Table 1.

Example 3 The graft efficiency was calculated by performing the same operations and treatments as in Example 1 except that 0.1 part by weight of dicumyl peroxide was added to the system before kneading. The reaction conditions and the reaction results are shown in Table 1.

Example 4 The graft efficiency was calculated by performing the same operations and treatments as in Example 1 except that the vinyl-based copolymer produced in Reference Example 2 was used in Example 1. The reaction conditions and the reaction results are shown in Table 1.

Example 5 100 parts by weight of EVA (equivalent to Example 1) and 100 parts by weight of the vinyl-based copolymer prepared in Reference Example 3 were preliminarily mixed, and 2
It was subjected to an extruder at 20 ° C. to obtain a pellet composition.
The graft efficiency was calculated in the same manner as in Example 1. The reaction conditions and the reaction results are shown in Table 1.

Example 6 100 parts by weight of EVA and the vinyl-based copolymer 50 produced in Reference Example 4
Dissolve parts by weight in 20 times the amount of xylene, stirrer, thermometer,
The mixture was transferred into a flask equipped with a condenser and a nitrogen gas introduction tube, reacted at 120 ° C. for 8 hours, cooled, xylene was distilled off under reduced pressure, and the residue was reprecipitated in methanol. After passing through the precipitate, it was dried under reduced pressure. The graft efficiency was calculated in the same manner as in Example 1. The reaction conditions and the reaction results are shown in Table 1.

Example 7 Using the vinyl-based copolymer produced in Reference Example 5 in Example 1, the same operation and treatment as in Example 1 were carried out except that 0.1 part by weight of dicumyl peroxide was added to the system before kneading.
Graft efficiency was calculated. The reaction conditions and the reaction results are shown in Table 1.

Comparative Example 1 Reference Example 6 in place of the vinyl-based copolymer in Example 1
Grafting efficiency was calculated by performing the same operations and treatments as in Example 1, except that the copolymer pendant only with the epoxy group prepared in 1. was used. The reaction conditions and the reaction results are shown in Table 1.

Comparative Example 2 5 parts by weight of glycidyl methacrylate and 1 part by weight of dicumyl peroxide were added to 100 parts by weight of EVA, and they were sufficiently mixed and homogenized. The same operations and treatments as in Example 1 were carried out. Graust efficiency was calculated. The reaction conditions and results at that time are shown in Table 1.

Example 8 Using a Brabender mixer, 100 parts by weight of ethylene propylene terpolymer (EPDM, Sumitomo Chemical Co., Ltd., Esprene 501A, ethylene ratio 65%) and 30 parts by weight of the vinyl-based copolymer produced in Reference Example 1 were used. The resin composition was obtained by kneading at 180 ° C. for 5 minutes.

This composition was dissolved in a predetermined amount of benzene, poured into 50 times (volume ratio) of acetone, and fractionally precipitated to calculate the grafting efficiency. The reaction conditions and the reaction results are shown in Table 2.

Example 9 The graft efficiency was calculated by the same operation and treatment as in Example 8 except that 0.1 part of dicumyl peroxide was added before kneading in Example 8. The reaction conditions and the reaction results are shown in Table 2.

Example 10 The grafting efficiency was calculated by performing the same operations and treatments as in Example 8 except that the vinyl-based copolymer produced in Reference Example 2 was used in Example 8. The reaction conditions and the reaction results are shown in Table 2.

Comparative Example 3 Reference Example 6 in place of the vinyl-based copolymer in Example 8
Grafting efficiency was calculated by performing the same operations and treatments as in Example 8 except that the copolymer having the pendant epoxy group prepared in 1. was used. The reaction conditions and the reaction results are shown in Table 2.

Example 11 Low-density polyethylene (LDPE, Ironmaking Chemical Industry Co., Ltd. Frozen G401, melt index 4 g / 10 min, density 0.927)
100 parts by weight of g / cm ² , melting point 112-118) and 30 parts by weight of the vinyl-based copolymer produced in Reference Example 1 were kneaded at 180 ° C. for 5 minutes using a Brabender mixer to obtain a resin composition.

This composition was dissolved in a predetermined amount of benzene at 70 ° C., poured into 20 times acetone and fractionally precipitated to calculate the grafting efficiency. The reaction conditions and the reaction results are shown in Table 2.

Example 12 100 parts by weight of polypropylene (PP, Floprene B200 manufactured by Iron and Steel Chemical Co., Ltd.) and 30 parts of the vinyl copolymer produced in Reference Example 1 were kneaded at 180 ° C. for 5 minutes using a Brabender mixer to prepare a resin composition. I got a thing.

This composition was dissolved in a predetermined amount of benzene at 70 ° C., poured into 20 times the amount of acetone and fractionally precipitated to calculate the grafting efficiency. The reaction conditions and the reaction results are shown in Table 2.

The examples and comparative examples show that the method of the present invention can very easily produce the desired epoxy group-grafted polyolefin copolymer.

Claims (1)

[Claims] 1. The following general formula (I): (Wherein R ₁ and R ₂ represent a hydrogen atom or a methyl group, and R ₃
Represents a linear alkyl group having 1 to 9 carbon atoms, a branched alkyl group, a phenyl group or an alkyl-substituted phenyl group having 1 to 3 carbon atoms. ) By mixing and heating the unsaturated peroxycarbonate and a copolymerizable monomer containing an epoxy group and an acrylic ester, and / or a vinyl-based copolymer composed of a styrene-based monomer and a polyolefin, A method for producing an epoxy group-grafted polyolefin copolymer, wherein the vinyl copolymer is grafted to a polyolefin.