JPH0813890B2 - Method for producing modified polyolefin - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a modified olefin polymer, and more particularly to a polysiloxane-modified olefin polymer having unique surface characteristics.

[Conventional technology]

It is conventionally known to add polysiloxanes to plastics. This addition prevents heat deterioration of the resin due to a decrease in molding temperature, improves productivity by shortening the molding cycle, improves stability of dimensional accuracy by preventing internal distortion of the molded product,
Improves the surface smoothness of molded products, improves workability by eliminating the need for mold release agents, prevents blocking during film molding, improves surface lubricity, improves surface abrasion resistance, and improves the appearance of surfaces such as gloss and gloss. It is aimed at improvement.

However, in addition to the above advantages, post-processing properties such as paintability, adhesiveness, vapor deposition property and printability are generally poor,
Further, when used as a packaging material or the like, there is a drawback that polysiloxane migrates to the contents and contaminates them. In order to correct these drawbacks, it has been attempted to use a group of polysiloxanes called olefin-modified polysiloxanes. However, when trying to improve paintability and printability, non-adhesiveness, non-adhesiveness, Since the lubricity is impaired, the balance must be balanced at a certain level, the performance is halfway, and the transfer stain is not sufficiently prevented.

Attempts have also been made to chemically bond polyolefins and polysiloxanes, which are premised on the formation of gel (for example, see JP-B-52-36898) and those which are carried out together with crosslinking (for example, JP-A-51). -33143, 53-1
2944, 55-71708, 50-94488, 57-53513, 52
-137684) is known. However, the copolymers obtained by these techniques cannot be put to practical use at all as a material for sheets, films, and other general molded articles that emphasize moldability and appearance.

Polyolefin is used as a packaging material in the form of sheets and films because it has good moldability and appearance, but since polysiloxane has the above-mentioned problems, it is used for sheets and films of packaging materials. It is not practically used as a modifying additive for polyolefins, and therefore, inorganic powder is used as a modifying additive.

[Problems to be Solved by the Present Invention]

An object of the present invention is to provide a polyolefin-based material excellent in moldability, appearance, non-adhesiveness, non-adhesiveness, lubricity and migration stain resistance without causing gel formation and / or cross-linking, particularly polysiloxane. A method of manufacturing a polyolefin conjugate is provided.

[Means for solving problems]

For the above-mentioned purpose, a polar functional group Z [Z is —OH, —NH ₂ , —
NHR ¹ (R ¹ is a hydrocarbon group having 1 to 20 carbon atoms), epoxy group, —COOH, acid anhydride group, acid halide group and —N
= C = O. ] Polysiloxane having
A polar functional group Y that reacts with this polar functional group Z [Y is -O
^{_{H, -NH 2, -NHR 2 (}} R 2 is a hydrocarbon group having 1 to 20 carbon atoms), an epoxy group, -COOH, anhydride group, selected from an acid halide group and -N = C = O . ], The polysiloxane having substantially no polar functional groups, the number N of polar functional groups Z being 1 to 10 on average per molecule, and the number M of polar functional groups Y. With a polyolefin having a molecular weight of 20 or less per molecule during the reaction
The ratio Nt / Mt (molar ratio) of the total amount Nt of Mt and the total amount Mt of Y is This is achieved by the method of the present invention in which a modified polyolefin is obtained by mixing and reacting both as follows.

Here, N is an average of the number of polar functional groups contained in one molecule of polysiloxane, and is usually obtained as a value obtained by dividing the average molecular weight by the value of the functional group equivalent. The functional group equivalent value can be known by chemical reaction titration of a fixed amount of polysiloxane or by obtaining the functional group concentration by a spectroscopic method. Here, the average molecular weight is the number average molecular weight. M is the average number of polar functional groups contained in one molecule of polyolefin, and N of polysiloxane
You can ask for it as well.

Polysiloxanes with polar functional groups Is a linear or branched (preferably linear) polymer having a main chain as a main component, and does not include a three-dimensional crosslinked body. The atom bonded to Si is an oxygen atom, a carbon atom or a hydrogen atom of a siloxy group (-O-Si ←), and the polar functional group described later is chemically bonded to the carbon atom in the oxygen atom. .

The average molecular weight of the polysiloxane used in the present invention is generally
It is 10 ³ to 10 ⁶ , and if this value is too small, the paintability and printability are poor, and the non-adhesiveness, non-adhesiveness, and lubricity are insufficient because the limit amount that can contain polysiloxane is low. In addition, the appearance of the molded product is deteriorated due to the generation of gel components and the like. If this value is too large, the reaction requires a remarkably extreme temperature and time, which is not economically preferable.

Molecules free of polar functional groups are virtually absent in the polysiloxane used in the present invention, and the value of N is 1-10, preferably 1-5. If the value of N is too low, paintability,
It is inferior in printability and stain resistance, and if the value of N is too large, the appearance of the molded product deteriorates. It is best to consist only of end-modified polysiloxanes with N = 1 or 2.

The polyolefin having a polar functional group has a composition
50 wt% or more 1-olefin having 12 or less carbon atoms (for example, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-
Decene, 1-dodecene, 3-methyl-1-butene, 4-
(Methyl-1-pentene, 3-methyl-1-pentene, etc.)
Further, a homopolymer or a copolymer obtained by radical copolymerization, ionic polymerization or coordination polymerization, in which a functional group as described below is bound to the main chain or the side chain is used.

The molecular weight of the polyolefin used in the present invention is generally 10
It is from 00 to 5 × 10 ⁶ , preferably from 5000 to 10 ⁶ . If this molecular weight is too small, the strength of the molded product will be poor, and if it is too high, the moldability will be poor, and the limit amount that can contain polysiloxane will be low, resulting in insufficient non-adhesiveness, non-adhesiveness and lubricity. .

The value of M, which indicates the amount of polar functional groups in the polyolefin, is
Generally, it is 0.01 to 20, preferably 0.1 to 10, and more preferably 0.5 to 5. If this value is too low, the limit amount that can contain polysiloxane will be low, and the non-adhesiveness, non-adhesiveness and lubricity will be unsatisfactory. Bring M
It is understood that polyolefins consisting only of = 1 are best, but for economic reasons it is not necessary to stick to M = 1.

The polar reactive groups contained in the polysiloxane, and _{polyolefins, -OH, -NH 3, -NHR (} R is 1 carbon atoms
~ 20 hydrocarbon groups), epoxy groups, -COOH, acid anhydride groups, acid halide groups and -N = C = O.
The following are mentioned as a combination of the polar functional group in polysiloxane and the polar functional group in polyolefin.

Here, R ^{1 to} R ⁴ are hydrocarbon groups having 20 or less carbon atoms.

Among the above combinations, from the viewpoint of easiness of reaction, --OH,
-NH ₂ or -NHR ¹ / -COOH, an acid anhydride group or -N =
C = O; epoxy group / -COOH or an acid anhydride group; an epoxy group ^{_{/ -NH 2, -NHR 2; -COOH}} / -N = C = O; and combinations of these reverse is preferred.

The basic structure of the polysiloxane having the polar functional group is represented by the following formula.

Here, R ^{5 to} R ⁷ are hydrocarbon groups having 8 or less carbon atoms, at least one of R ⁵ and R ⁶ and R ⁷ are preferably methyl groups.

Examples of the polysiloxane include epoxy modified silicone oil, amino modified silicone oil, carboxyl modified silicone oil, alcohol modified silicone oil, terminal alcohol type polyether modified silicone oil, and copolymers thereof. More specific examples thereof include polydimethylsiloxane / poly (methylglycidoxypropyl) siloxane copolymer, polydimethylsiloxane / poly (methylaminopropyl) siloxane copolymer, polydimethylsiloxane / poly (methylhydroxy). Carbonylpropyl) siloxane copolymer, polydimethylsiloxane-poly (methylhydroxypropyl) siloxane copolymer, α, ω-glycidoxypropylpolydimethylsiloxane, α, ω-aminopropylpolydimethylsiloxane, α, ω-hydroxy Examples include propyl polydimethyl siloxane.

In addition, as the polysiloxane having a polar functional group,
Those in which a plurality of modified polysiloxanes as described above are chemically bonded are also included. That is, a compound represented by the following formula in which α, ω-modified polysiloxane is chemically bonded is also suitable.

As the polyolefin, a substance obtained by polymerizing the above-mentioned olefin has a main structure, and specifically, polyethylene, polypropylene, poly-1-butene, polyisobutylene, polypentene, poly-3-methyl-1-butene,
Poly-4-methyl-1-pentene, poly-3-methyl-
1-Pentene, a copolymer of ethylene and another olefin (for example, ethylene-propylene rubber, a crystalline polymer containing a small amount of butene or propylene, hexene or octene,
Crystalline polypropylene containing a small amount of ethylene, poly-
1-butene) and copolymers of olefins other than ethylene (for example, propylene-butene, butene-4-methyl-1-pentene, propylene-hexene, etc.).

A known method may be used as the method for introducing the functional group into these polyolefins, and the following examples can be given.

Monomers having the above-mentioned functional groups during the polymerization of olefins (eg acrylic acid, methacrylic acid, glycidyl methacrylate, maleic anhydride, hydroxyethyl acrylate, aminoethyl acrylate, vinylamine, etc.)
And a method of deriving it from a functional group being copolymerized (for example, converting an ester into an alcohol or an acid) in the presence of the functional group monomer, a radical generator (a known organic peroxide can be used) Of degrading and grafting, a method of chemically reacting active polymer chain ends after coordination polymerization or an ionic polymerization reaction, a method of using the one containing the functional group as a termination reaction agent during radical polymerization, a radical polymerization Examples of the method include using an initiator containing the functional group as the initiator.

The reaction between the polysiloxane having a polar functional group and the polyolefin may be carried out by simply mixing the two and can be easily carried out by a known device and method. of course,
As is well known, the reaction between macromolecules is slower than that of small molecules, so the temperature is high, usually 100 to 350 ° C, preferably 150 to 300 ° C. Further, in order to improve the mixing between the both, it is preferable to stir, mix and knead well, and it is also preferable to use an appropriate solvent in consideration of economic efficiency to reduce the viscosity of the system and to carry out the reaction.

The presence of unreacted polyolefin is not a hindrance in many cases, but the presence of unreacted polysiloxane is unfavorable from the viewpoints of poor coatability and printability and migration stain resistance. In consideration of economy, removal by solvent washing or solvent fractionation often gives preferable results. However, in the case of the present invention, practical performance can be satisfied without necessarily requiring this removing operation. To eliminate the need for removal,
It is known that when the reaction is allowed to proceed completely, a gelling reaction occurs when N or M contains 3 or more raw materials, and the above-mentioned adverse effects are caused. Normally, it seems that these conflicting requirements cannot be satisfied, but in the method of the present invention, it can be unexpectedly satisfied, which is surprising from the common sense of polymer chemistry.

In order to better express the effects of the present invention, in addition to the requirements relating to polysiloxane and polyolefin, it is necessary to control the ratio of the total amount Nt of functional groups derived from polysiloxane to the total amount Mt of polar functional groups in the polyolefin during the reaction. Yes, Good results are obtained at. This ratio is When it is larger, defects such as deterioration of printability and paintability and migration stain resistance appear. This value becomes smaller as the value of Mt becomes larger. In this case, there is no particular defect in performance, but it is preferable to set it to Nt / Mt 0.0001 from the viewpoint of economy. More preferably, it is 0.001 Nt / Mt 0.8.

The weight ratio of polyolefin to polysiloxane during the reaction is usually 99.9 / 0.1 to 70/30, preferably 99.5 /
0.5 to 80/20. If this value is too high, the lubricity is low, and if it is too low, it has stain resistance, impairing paintability and printability.

〔The invention's effect〕

The modified polyolefin obtained by the method of the present invention does not cause thermal deterioration due to the low molding temperature, has high productivity because the molding cycle is shortened, and has excellent surface smoothness of the molded article,
It does not require a mold release agent, so it has good workability, does not cause blocking when molding films, has excellent surface lubricity and surface abrasion resistance, and has an excellent appearance such as gloss and gloss on the surface. . Moreover, it has good paintability and printability.

〔Example〕

Hereinafter, the present invention will be described specifically with reference to examples. In the examples, “%” means “% by weight”.

Example 1 Production of polar functional group-containing polyolefin Homopolypropylene powder (MFI = 0.1) (di-t-butylhydroxytoluene [hereinafter abbreviated as “BHT”] 0.1% as a stabilizer, tetrakis [methylene-3- (3 ′, 5'-
Di-t-butyl-4′-hydroxyphenyl) propionate] methane (hereinafter abbreviated as “Irg 1010”) 0.1%,
100 g of calcium stearate (containing 0.1%) was mixed with 400 g of benzoyl peroxide and 400 g of maleic anhydride and pelletized at 210 ° C. in a 40 mm extruder. The amount of maleic anhydride grafted in the obtained maleic anhydride graft-modified polypropylene was 2 × 10 ⁻⁵ mol / g as determined by IR method, and the MFI was 4.2.

Manufacture of modified polyolefin 3kg of amino-modified polysiloxane (α, ω-aminopropylpolydimethylsiloxane, amino equivalent 12,000, average molecular weight 24,000) and 57kg of maleic anhydride graft-modified polypropylene are mixed and pelletized at 180 ° C with a 40mm extruder. Turned into After being repeatedly passed through the extruder (total residence time of the resin was 10 minutes), the MFI of the obtained resin was 3.8 and the content of polysiloxane unit was 5% (Si content in the resin was determined by fluorescent X-rays). It was determined by measuring).

Measurement of Graft Ratio The graft ratio was measured according to the following procedure using methyl ethyl ketone, which is a solvent that dissolves amino-modified polysiloxane, but hardly dissolves modified polypropylene, and xylene, which is a common solvent for amino-modified polysiloxane and modified polypropylene.

20 g of the modified polyolefin is dissolved in 400 cc of heated xylene. This solution is poured into 2 l of cold methyl ethyl ketone with stirring and allowed to cool to room temperature. The powdery resin was filtered off, thoroughly washed with methyl ethyl ketone, and dried under reduced pressure.
The amount of Si in the product was determined by fluorescent X-ray measurement, the ratio of the amount of Si in the original modified polyolefin was calculated, and this number was taken as the graft ratio. In the above example, it was 78%.

Film forming and testing Put the above modified polyolefin on a 30mm water-cooled blown film forming machine, folding width 25cm, thickness 50μ
m film was obtained.

The obtained film was observed and the number of gels and fish eyes having a diameter of 0.5 mm or more was examined and converted into the number per square foot. The dynamic friction coefficient μk of the above film is determined by ASTM D-18
The measurement was carried out by the method of 94 under the condition of a moving speed of 150 mm / min.

In addition, this film is used with 6 nylon T-die film and 23
The surface wetting tension γ of 6-nylon after contacting at 10 ° C. for 10 days and releasing was determined by the method of JIS K6768.

These measured values are shown in Table 1. By comparing with the comparative example described later, it is found that the film is excellent without gel, has excellent lubricity, and has no migration stain property (indicated as "fouling property" in the table).

Examples 2 and 3 and Comparative Examples 1 and 2 The polysiloxane used in Example 1 was replaced by α, ω-dihydroxypropylpolydimethylsiloxane (Example 2),
An inflation film was prepared in the same manner as in Example 1 except that α, ω-diglycidoxypropylpolydimethylsiloxane (Example 3) or unmodified polysiloxane (Comparative Example 1) was used or polysiloxane was not used (Comparative Example 2). Obtained. The results are shown in Table 1.

Comparative Example 3 BHT 0.1%, Irg1010 0.1%, calcium stearate 0.
Using only polypropylene containing 1% (MFI = 5),
An inflation film was obtained in the same manner as in Example 1 without using the modified polysiloxane. The results are shown in Table 1.

Comparative Examples 4 and 5 The same polypropylene as that used in Comparative Example 3 was used except that MFI = 3, and the same polysiloxane as in Example 1 was used (Comparative Example 4) or unmodified polydimethylsiloxane (Comparative). An inflation film was obtained in the same manner as in Example 1 using Example 5). The results are shown in Table 1.

Example 4 Random Copolymerized Polypropylene Powder Containing 6% Ethylene Units (BHT 0.1%, Irg1010 0.1%, Calcium Stearate 0.
A film was prepared in the same manner as in Example 2 except that 1% of MFI = 0.1) was used instead of the homopolypropylene powder. The results are shown in Table 1.

Example 5 In the production of a polar functional group-containing polyolefin, MI
(190 ° C.) = 26 Polyethylene powder (containing 0.02% BHT) was used instead of the homopolypropylene powder, and the amount of benzoyl peroxide was changed to 10 g and the amount of maleic anhydride was changed to 200 g. I made a film. The results are shown in Table 1.

Example 6 As a polar functional group-containing polyolefin, copolymerized polyethylene obtained by a high-pressure radical polymerization method (MI = 8, methylmethacrylate unit 4%, maleic anhydride unit 0.1)
% Content, BHT 0.01% content) was used to prepare a film in the same manner as in Example 1. The results are shown in Table 1.

Example 7 The same as Example 1 except that copolymerized polyethylene (MI = 7, containing 0.1% of acrylic acid unit, containing 0.01% of BHT) obtained by a high pressure radical polymerization method was used as the polar functional group-containing polyolefin. I made a film. The results are shown in Table 1.

Example 8 A film was produced in the same manner as in Example 1 except that 100 g of glycidyl methacrylate was used instead of maleic anhydride during the production of the polar functional group-containing polyolefin. The results are shown in Table 1.

Example 9 0.24 kg of hexamethylene diisocyanate was added to 8 kg of α, ω-diaminopropylpolydimethylsiloxane (amino equivalent 2300, molecular weight 4600), and the mixture was heated and stirred at 150 ° C. for 2 hours. A film was prepared in the same manner as in Example 1 except that the terminal amino-modified polysiloxane obtained by this method was used as the modified polysiloxane. The results are shown in Table 1.

Claims (1)

[Claims] 1. A polar functional group Z [Z is --OH, --NH ₂ , --NHR ¹
(R ¹ is a hydrocarbon group having 1 to 20 carbon atoms), an epoxy group,-
COOH, acid anhydride group, acid halide group and -N = C =
Selected from O. ] And a polar functional group Y that reacts with the polar functional group Z [Y is -OH, -N
H ^_2, -NHR ₂ (R ₂ is a hydrocarbon group having 1 to 20 carbon atoms), an epoxy group, -COOH, anhydride group, selected from an acid halide group and -N = C = O. ], A polysiloxane having substantially no polar functional group, wherein the number N of polar functional groups Z is 1 to 10 on average per molecule, and the number M of polar functional groups Y. 20 per molecule
The ratio Nt / Mt (molar ratio) of the total amount Nt of Z and the total amount Mt of Y at the time of the reaction A method for producing a modified polyolefin, characterized in that both are mixed and reacted as follows.