JPS6360041B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is capable of aging at high temperatures, which is required for conventional antistatic agents, when it is blended into olefin polymers such as olefin homopolymers or copolymers, or other synthetic polymer materials and molded. It has the advantage that it has excellent performance in terms of the expression and sustainability of the antistatic effect even without post-treatment such as or corona treatment, and has no adverse effect on the properties of the polymer material. The present invention relates to a novel carbobetaine-modified olefin polymer useful as an antistatic agent and an antistatic agent comprising the carbobetaine-modified olefin polymer. Olefin polymers such as olefin homopolymers or copolymers, and other hydrophobic synthetic polymer materials are easily charged with static electricity. As a result, when producing films, sheets, fibers, and other molded articles from such polymeric materials, or during post-processing or post-treatment of these molded articles, or when using the resulting products, Dust absorption, generation of sparks,
Another disadvantage is that problems due to charging are likely to occur. Attempts have been made for some time to prevent electrostatic charging of such hydrophobic synthetic polymer materials. For example, "Antistatic agent" written by Hideo Marumo,
Various antistatic agents have been developed and used, as described in, for example, published by Saiwai Shobo. However, there is still nothing that is fully satisfactory in terms of performance and ease of use, and the search for it is still ongoing. Conventionally, for example, betaine-type antistatic agents have been disclosed in Japanese Patent Publications No. 1645-1973, Japanese Patent Publication No. 14654-1973,
This method has been proposed in Japanese Patent Publication No. 50-29928 and is well known. However, even if such betaine type antistatic agents are blended and molded into a molded product, such as a film, it is difficult to obtain the desired antistatic effect. In order to develop an antistatic effect after uniaxially or biaxially stretching, a method of applying a surface activation treatment such as corona treatment is disclosed in Japanese Patent Publication No. 44-29757, Japanese Patent Publication No. 49-5746, or Japanese Patent Publication No. 49-5746. This was proposed in Japanese Patent Publication No. 50-33827. However, these methods require complicated operations and disadvantageous surface activation treatment means, and the antistatic effect is not maintained because the antistatic agent is eluted from the molded product when it comes into contact with water. There are disadvantages such as lack of sexuality. In addition, Special Publication No. 46-30293 and Special Publication No. 49
Publication No. 26955 discloses a method for producing a polymer or copolymer containing an unsaturated monomer containing a carbobetaine type functional group, and also discloses a method for producing a polymer or copolymer containing an unsaturated monomer containing a carbobetaine type functional group. It is stated that the combination can be used as a permanent antistatic agent. However, the polymers or copolymers containing the carbobetaine-type functional group-containing unsaturated monomers disclosed in these known documents cannot be used as olefin polymers such as olefin homopolymers or copolymers such as polyethylene and polypropylene. Even if the polymer or copolymer containing the carbobetaine type functional group-containing unsaturated monomer unit is poor in compatibility with the olefinic polymer, sufficient antistatic effect may not be obtained. There are many other drawbacks, such as the inability to obtain For example, even if a molded article such as a film is made from an olefinic polymer blended with a polymer or copolymer containing the carbobetaine-containing unsaturated monomer component unit, corona The polymer or copolymer containing the carbobetaine-containing unsaturated monomer unit may be eluted if surface activation treatment such as treatment is required, or if the molded product is brought into contact with steam, water, or other solvents. However, there are drawbacks such as the durability of the antistatic effect is significantly reduced. The present inventors have discovered that when molded into synthetic polymer materials such as olefin homopolymers or copolymers of olefin, conventionally known betaine-type antistatic agents and carbobetaine-type functional group-containing Unlike antistatic agents made of polymers or copolymers containing saturated monomers, it does not require special surface activation treatment, and it also exhibits antistatic effect and maintains its effect. Excellent in
We conducted research and development on an antistatic agent that can be manufactured at low cost. As a result, the present invention discloses that a carbobetaine-modified olefin-based polymer to which a carbobetaine-type functional group having a special structure is bonded is a new substance, and that this carbobetaine-modified olefin-based polymer is a conventionally known betaine-type charged polymer. It has been found that the above-mentioned drawbacks or difficulties of polymers or copolymers containing unsaturated monomer component units containing inhibitors or carbobetaine-type functional groups can be completely overcome and exhibit excellent antistatic performance. It is based on In particular, molded products containing the carbobetaine-modified olefin polymer of the present invention can be easily treated without special surface activation treatment such as corona treatment.
A polymer that exhibits a sufficient antistatic effect immediately after molding and has an excellent sustainability of the effect, and furthermore contains a conventionally known betaine type antistatic agent or a carbobetaine type functional group-containing unsaturated monomer component unit. Or, compared to copolymers, it has better compatibility with synthetic polymer materials such as olefin polymers, does not reduce the blocking properties of molded products such as films and sheets, and does not cause surface stickiness, etc. It does not degrade the performance of the base synthetic polymer material such as surface printability or gloss, it does not easily detach from the molded product even when it comes into contact with other substances, and it does not come into contact with steam, water, or other solvents. This is based on the discovery that the carbobetaine-modified olefin polymer is less likely to be eluted even when the olefin polymer is modified, so that it has advantages such as good sustainability of the antistatic effect. That is, the present invention provides α-
At an unspecified carbon atom of an olefin polymer base resin consisting of olefin component units, and/or general formula [] (In formula [] and formula [], R ¹ represents an alkylene group having 1 to 3 carbon atoms, R ² represents a methylene group, R ³ and R ⁴ each represent an alkyl group having 1 to 2 carbon atoms, R ⁵ to R ⁶ each represent a hydrogen atom, R ⁷ represents a hydrogen atom,
X represents an oxygen atom or >NH. ) is 0.05 to 0.25 per 100 g of the carbobetaine-modified olefin polymer.
It is a carbobetaine-modified olefin polymer which is grafted in molar equivalents (average of 0.25 to 62.5 grafts per base resin molecule) and whose number average molecular weight is in the range of 500 to 25,000. The present invention also relates to an invention for the use of the carbobetaine-modified olefin polymer, and relates to an antistatic agent comprising the carbobetaine-modified olefin polymer. The carbobetaine-modified olefin polymer of the present invention has the above general formula [] and/or a carbon atom of a base resin made of an olefin polymer mainly composed of α-olefin component units having 2 to 6 carbon atoms.
or is unique in that a carbobetaine type functional group represented by the general formula [] is bonded,
It is clearly distinguished from conventional polymers or copolymers containing unsaturated monomer component units containing carbobetaine type functional groups. The carbobetaine-modified olefin polymer of the present invention is produced, for example, by modifying a base resin consisting of an olefin polymer whose main component is an α-olefin unit having 2 to 6 carbon atoms. The olefinic polymer of the base portion that is introduced into the carbobetaine-modified olefinic polymer of the present invention is:
It is an olefin polymer whose main component is an α-olefin component unit having 2 to 6 carbon atoms, and the α-
The content of olefin component units is preferably in the range from 70 to 100 mol%, particularly preferably in the range from 80 to 100 mol%. Specifically, it is composed of a homopolymer of α-olefin having 2 to 6 carbon atoms or a copolymer thereof, an α-olefin component unit having 2 to 6 carbon atoms, and an α,β-unsaturated polar compound component unit. And it is a copolymer containing the olefin component unit as a main component. The olefinic polymer used as the base resin usually has a number average molecular weight of about 300 to about 80,000, preferably about 300 to about 80,000.
22000, molecular weight distribution (w/n)
is usually in the range of about 1.0 to about 10, preferably about 1.1 to about 8. Specifically, the α-olefin component having 2 to 6 carbon atoms constituting the carbobetaine-modified olefin polymer of the present invention and constituting the olefin polymer of the base resin includes, for example, ethylene, propylene, 1-butene, Examples include 4-methyl-1-pentene, and one or two of these
It can also be used as a mixture of more than one species. Specifically, the olefinic polymer that is introduced into the carbobetaine-modified olefinic copolymer of the present invention and serves as its base resin includes polyethylene,
Polypropylene, poly-1-butene, poly-4-
Homopolymers of α-olefins such as methyl-1-pentene, ethylene/propylene copolymers, ethylene/1-butene copolymers, ethylene/4-methyl-1-pentene copolymers, ethylene/butadiene copolymers , ethylene/propylene/diene copolymer, propylene/ethylene copolymer, propylene/1-butene copolymer, propylene/4-methyl-1-pentene copolymer, etc. as the main component. Examples include polymers. The carbobetaine-modified olefin polymer of the present invention has the general formula [] and/or general formula [] This is a carbobetaine-modified olefin polymer having a structure in which carbobetaine-type functional groups represented by the following formula are bonded. That is, it is bonded to an unspecified carbon atom constituting the trunk of the base resin and/or is bonded to an unspecified carbon atom of a branch of the base resin having a branched structure. Here, in both formulas, R ¹ represents an alkylene group having 1 to 3 carbon atoms, R ² represents a methylene group, R ³ and R ⁴ each represent an alkyl group having 1 to 2 carbon atoms, and R ⁵ and R ⁶ each represents a hydrogen atom, R ⁷ represents a hydrogen atom, and X represents an oxygen atom or >NH. Said general formula [] and/or general formula []
The following are examples of the functional groups constituting the carbobetaine type functional group represented by:
Specifically, R ¹ includes a methylene group, an ethylene group,
Examples include propylene groups. ^R3
and R ⁴ specifically represent a hydrogen atom,
Examples include methyl group and ethyl group. Said general formula [] and/or general formula []
In the carbobetaine type functional group represented by,
R ⁷ is R ¹ in the carbobetaine type functional group or
Depending on the chain length of R ² , it binds to either carboxylate anion [-COO], but it does not matter whether it binds to any carboxylate anion. Said general formula [] and/or general formula []
Specifically, the carbobetaine type functional group represented by, for example, The content of the carbobetaine-type functional group represented by the general formula [] and/or general formula [] contained in the carbobetaine-modified olefin polymer of the present invention is as follows: (calculated in conjunction with the number average molecular weight range described below, an average of 0.25 to 62.5 such carbobetaine-type functional groups are grafted per base resin molecule). The number average molecular weight of the carbobetaine-modified olefin polymer of the present invention must be in the range of 500 to 25,000. When the number average molecular weight of the carbobetaine-modified olefin-based polymer is less than about 500, when the composition obtained by blending the carbobetaine-modified olefin-based copolymer into a synthetic polymer material is molded, the carbobetaine The modified olefin polymer bleeds out onto the surface of the molded product, making the surface sticky, or when the surface of the molded product comes into contact with water, the carbobetaine-modified olefin polymer tends to elute, reducing the sustainability of the antistatic effect. becomes inferior. In addition, if the number average molecular weight of the carbobetaine-modified olefin polymer is greater than 25,000, it will be difficult to uniformly disperse it into the synthetic polymer material when it is blended into the material and molded, resulting in sufficient antistatic performance. or the appearance of the molded product may deteriorate. The molecular weight distribution (w/n) of the base resin of the carbobetaine-modified olefin polymer is usually 1.0 to 10, preferably
It ranges from 1.1 to 8. The number average molecular weight of the carbobetaine-modified olefin polymer of the present invention is the number average molecular weight of the olefin polymer of the base resin before modification, and the structure of the carbobetaine-type functional group constituting the carbobetaine-modified olefin polymer. It was also calculated from the content. Further, the number average molecular weight of the olefin polymer of the base resin before modification was measured using a vapor pressure osmometer (manufactured by Knawell). Further, the molecular weight distribution of the carbobetaine-modified olefin polymer of the present invention was measured by gel permeation and chromatography (manufactured by Waters). Further, the composition of each component unit constituting the carbobetaine-modified olefin polymer of the present invention and the olefin polymer of the base resin before modification can be determined from the results of nuclear magnetic resonance spectroscopy of each polymer. Further, the content of the carbobetaine type functional group of the present invention was determined by calculation from the nitrogen content determined by microanalysis. The carbobetaine-modified olefin polymer of the present invention can be produced by the following method. The first method is to add the above-mentioned olefin polymer with the general formula [] (In the formula, R ⁵ and R ⁶ both represent the same groups as above.) α,β-unsaturated dicarboxylic acid anhydride or general formula [] (In the formula, R ⁵ , R ⁶ and R ⁷ all represent the same groups as above.) By graft copolymerizing an α,β-unsaturated dicarboxylic acid and/or a derivative thereof, the olefin General formula for the system polymer [] (In the formula, R ⁵ and R ⁶ both represent the same groups as above.) α,β-unsaturated dicarboxylic acid anhydride modified with α,β-unsaturated carboxylic acid anhydride component units bonded Olefin polymer, or the general formula [] for the above olefin polymer (In the formula, R ⁵ , R ⁶ and R ⁷ all represent the same groups as above.) An olefinic polymer modified with a saturated dicarboxylic acid or its derivative (these are referred to as an intermediate modified olefinic polymer [A]) is obtained. Furthermore, these intermediate modified olefin polymers [A] have the general formula [] (In the formula, R ¹ , R ³ and R ⁴ each represent the same group as above.) or the general formula [] (In the formula, R ¹ , R ³ and R ⁴ each represent the same group as above.) By reacting the N,N-disubstituted alkylene diamine represented by the general formula [] and/or general formula [] (In formula [] and formula [], R ¹ , R ³ ,
R ⁴ , R ⁵ , R ⁶ , R ⁷ and X all represent the same groups as above. ) An intermediate modified olefinic polymer (hereinafter referred to as an intermediate modified olefinic polymer [B]) to which α,β-unsaturated dicarboxylic acid derivative component units represented by (a) are bonded is produced. Intermediately modified olefin polymer [B] thus obtained
In addition, the general formula [XI] Y-R ² -COOR ⁷ [XI] (wherein, R ² represents the same group as above, Y represents a halogen atom, and R ⁷ represents the same group as above) .) By reacting a salt of a halogenated lower aliphatic carboxylic acid or an ester thereof, the carboxylic acid of the present invention containing a carbobetaine-type functional group represented by the general formula [] and/or the general formula [] can be obtained. A betaine-modified olefin polymer is obtained. Further, as the second manufacturing method, the following method can be exemplified. The olefinic polymer of the base resin has α,β- represented by the general formula []
The intermediate modified olefinic polymer [A] obtained by graft copolymerizing an unsaturated dicarboxylic acid anhydride or an α,β-unsaturated dicarboxylic acid represented by the general formula [] and/or a derivative thereof, Formula [XII] (In the formula, R ¹ , R ² , R ³ and R ⁴ all represent the same groups as above.) By reacting N-hydroxyalkylcarbobetaine represented by the general formula [] and the general formula The carbobetaine-modified olefin polymer of the present invention containing a carbobetaine-type functional group in which X is an oxygen atom is obtained. Further, the intermediate modified olefin polymer [A] has the general formula [] (In the formula, R ¹ , R ² , R ³ and R ⁴ all represent the same groups as above.) By reacting N-aminoalkylcarbobetaine,
The carbobetaine-modified olefin polymer of the present invention containing a carbobetaine-type functional group in which X is >NH in the general formula [] and/or [] is obtained. Furthermore, the following method can be exemplified as the third manufacturing method. The olefin polymer of the base resin has the general formula [] and/or general formula [] (In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and X are the same groups as above.) By graft copolymerizing the saturated dicarboxylic acid derivative component, the carbobetaine-modified olefin polymer of the present invention containing a carbobetaine-type functional group represented by the general formula [] and/or the general formula [] can be obtained. The carbobetaine-modified olefin polymer of the present invention is used as an antistatic agent with excellent performance as described above. The use as an antistatic agent will be explained next. The modified olefin-based copolymer used as an antistatic agent is the carbobetaine-modified olefin-based polymer described above, and among the carbobetaine-modified olefin-based polymers of the present invention, the modified olefin-based copolymer has properties suitable as an antistatic agent. The olefin polymer is also as described above. Specifically, examples of synthetic polymer materials that are effective when using the antistatic material of the present invention include polyethylene, polypropylene,
Poly-1-butene, poly-4-methyl-1-pentene, polystyrene, ethylene/propylene copolymer, ethylene/1-butene copolymer, ethylene/4-methyl-1-pentene copolymer, ethylene/acetic acid Examples include polyolefins such as vinyl copolymers, polyamides, polyesters, polyvinyl chloride, polycarbonates, ABS, AS acrylic resins, acrylonitrile resins, polyurethanes, phenolic resins, melamine resins, and urea resins. Among these synthetic polymer materials,
Particularly excellent effects are observed when the antistatic agent of the present invention is blended with polyolefins such as olefin-based polymers such as olefin homopolymers or copolymers. The method of blending the antistatic agent of the present invention with the synthetic polymer is not particularly limited, and any method may be used. For example, it is also possible to adopt a method of uniformly blending the powder, pellets, etc. of a synthetic polymer material with other additives as necessary to a predetermined concentration. At this time, it is also possible to adopt a method in which the antistatic agent is dissolved or suspended in a solvent and blended into the synthetic polymer material, and then the solvent is distilled off. The blending ratio of the antistatic agent of the present invention to be blended into the synthetic polymeric material varies depending on the type of antistatic agent, the content of the carbobetaine type functional group, the type of synthetic polymeric material, its use, etc. , 100g of synthetic polymer material
The amount of the carbobetaine-type functional group relative to the total amount is usually in the range of 0.01 to 300 mmol, preferably 0.05 to 250 mmol. The method of blending the antistatic agent of the present invention into the synthetic polymer material is not particularly limited, but for example, a master batch containing the synthetic polymer material at a high concentration is prepared in advance, and this is added to the synthetic polymer material. It is also possible to adopt a method in which the olefin monomer is blended into the olefin monomer, or in some cases, it can be added during the polymerization of the olefin monomer. When blending the antistatic agent of the present invention into the synthetic polymer material, in addition to the antistatic agent of the present invention, antioxidants, ultraviolet absorbers, lubricants, plasticizers, mold release agents, flame retardants, or other additives may be added. It can also be blended with an antistatic agent. The composition of the synthetic polymer material containing the antistatic agent of the present invention is used after being molded into various forms.
For example, it is formed into films, stretched films, tapes, stretched tapes, sheets, fibers, and other three-dimensional molded products. Among these molded products, it is preferable to mold a synthetic polymer composition containing the antistatic agent of the present invention into a film, stretched film, tape, stretched tape, sheet, or fiber. A molded article made from a composition made of a synthetic polymer material containing the antistatic agent of the present invention has a higher performance than a molded article made from a composition made from a synthetic polymer material containing a conventional betaine type antistatic agent. , an excellent antistatic effect appears immediately without special surface activation treatments such as corona treatment or aging at temperatures above the glass transition point, and the antistatic agent remains intact even when the surface comes into contact with water or solvents. In addition to being characterized by good durability of the effect because it does not elute, it does not reduce the performance of the base polymer material such as blocking properties, printability on the surface, and gloss, and it does not affect the surface finish. It has the advantage of not causing stickiness or the like. Next, the carbobetaine-modified olefin polymer of the present invention and the antistatic agent comprising the modified olefin polymer will be specifically explained with reference to Examples. Example 1 Polyethylene wax (number average molecular weight 1100,
w/n2.5) Pour 200g into a 500c.c. glass reactor equipped with a stirring blade and a cooling tube, heat it to 190℃ to melt the wax, replace the system with nitrogen, and then stir under strong stirring. 31.4 g of maleic anhydride and 1.5 g of ditertiary butyl peroxide were added dropwise over 4 hours, and the reaction was continued for 2 hours. Immediately after the reaction was completed, the reaction mixture was taken out into a vat and allowed to cool to room temperature. Crush this and make about 1
After heating and dissolving in DMF and allowing to cool to room temperature, the reaction mixture was precipitated in a large excess of acetone to obtain an intermediate modified polymer, which was thoroughly washed with acetone and dried under reduced pressure at room temperature overnight.201.2 An intermediate modified polymer of g was obtained. The maleic anhydride content of this intermediately modified polymer was calculated from the oxygen content in the intermediately modified polymer, and was 1.3 mmol/g, and the number average molecular weight was 1,250. Next, 10.8 g of a reaction reagent [HOCH ₂ CH ₂ N(CH ₃ ) ₂ COO] synthesized by reacting dimethylethanolamine [HOCH ₂ CH ₂ N (CH ₃ ) ₂ ] with sodium monochloroacetate, and 20 g of intermediate modified polymer. and DMF200c.c. were placed in a 500c.c. glass reactor equipped with a stirring blade and a cooling pipe, and after purging the system with nitrogen, the temperature was raised to 140℃.
The reaction was allowed to proceed for 8 hours while stirring. After the reaction was completed, the reaction mixture was allowed to cool to room temperature, and the resulting polymer was precipitated with a large excess of methanol. The resulting polymer was washed three times with a mixed solvent of water and methanol, and then thoroughly washed with acetone, and then heated at 50°C under reduced pressure. Leave it to dry for a day and night, then apply the formula. The carbobetaine type functional group content expressed as
1 mmol/g (calculated from nitrogen content by microanalysis.
same as below. ) carbobetaine modified polymer 21.8
I got g. This carbobetaine-modified polymer had 90% of the acid anhydride groups of the intermediate modified polymer modified to carbobetaine-type functional groups, and had a number average molecular weight of 1,500. The introduction of the carbobetaine type functional group was also confirmed from a characteristic absorption peak at about 1620 cm ^-1 in infrared absorption spectrum analysis (the same applies to the following examples). This carbobetaine-modified polymer is referred to as antistatic agent A. Example 2 Reaction reagent synthesized from N,N-dimethyl-1,3-propanediamine [H ₂ NCH ₂ CH ₂ CH ₂ N(CH ₃ ) ₂ ] and sodium monochloroacetate [H ₂ NCH ₂ CH ₂ CH ₂ N( _CH3 ) _{2CH2COO 〕}
10.6g and intermediate modified polymer 20 synthesized in Example 1
g and DMF200c.c. were placed in a 500c.c. glass reactor equipped with a stirring blade and a cooling tube, and after purging the system with nitrogen, the temperature was raised to 140°C with stirring, and the reaction was continued for 5 hours. I let it happen. After the reaction was completed, the reaction mixture was allowed to cool to room temperature and precipitated with a large excess of methanol. The resulting polymer was thoroughly washed several times with a mixed solvent of water and acetone and acetone, and then dried under reduced pressure at 50°C overnight. ,formula and The carbobetaine type functional group content expressed as
0.7 mmol/g carbobetaine modified polymer 21.2
I got g. This carbobetaine-modified polymer had 65% of the acid anhydride groups of the intermediately modified polymer modified and had a number average molecular weight of 1,400. This carbobetaine-modified polymer is referred to as antistatic agent B. Example 3 Diethylethanolamine [HOCH ₂ CH ₂ N
(C ₂ H ₅ ) ₂ ] and sodium monochloroacetate [HOCH ₂ CH ₂ N
(C ₂ H ₅ ) ₂ CH ₂ COO] 16.6 g, 20 g of the intermediate modified polymer synthesized in Example 1, and 200 c.c. of DMF were charged into a 500 c.c. glass reactor equipped with a stirring blade and a cooling tube, and the mixture was stirred. After replacing the system with nitrogen,
The temperature was raised to 140°C and the reaction was carried out for 3 hours. After the reaction was completed, the same post-treatment as in Example 1 was carried out to obtain the formula The content of carbobetaine type functional group represented by
0.7 mmol/g carbobetaine modified polymer 21.4
I got g. This carbobetaine-modified polymer had 60% of the acid anhydride groups of the intermediately modified polymer modified and had a number average molecular weight of 1,400. This carbobetaine-modified polymer is referred to as antistatic agent C. Example 4 Polyethylene wax (number average molecular weight 2000,
50 g of w/n3) and 200 g of o-dichlorobenzene were charged into a 500 c.c. glass reactor equipped with a stirring blade and a cooling tube, and after purging the system with nitrogen, the temperature was raised to 140° C. while stirring. 17.2 g of maleic anhydride and 0.7 g of ditertiary butyl peroxide were added dropwise into the solution over 4 hours, and the reaction was allowed to continue for another 2 hours. After completion of the reaction, the reaction mixture was allowed to cool to room temperature, and the reaction mixture was precipitated in a large excess of acetone. The raw material polymer obtained was thoroughly washed with acetone, and the mixture was heated at 100°C under reduced pressure overnight. Dry, maleic anhydride content
59 g of an intermediate modified polymer having a number average molecular weight of 2200 and a concentration of 0.96 mmol/g was obtained. Next, 20 g of this intermediate modified polymer, a carbobetaining agent [H ₂ NCH ₂ CH ₂ CH ₂ N(CH ₃ ) ₂ CH ₂ COO
] 12g, paraxylene 300c.c. and dimethyl sulfoxide 150c.c. 1 with stirring blade and cooling pipe attached
The mixture was charged into a glass reactor, and after purging the system with nitrogen, the temperature was raised to 135°C while stirring, and the reaction was allowed to proceed for 6 hours. After the reaction was completed, the reaction mixture was allowed to cool to room temperature, and the same post-treatment as in Example 1 was performed to obtain the formula The content of carbobetaine type functional group represented by
0.8 mmol/g carbobetaine modified polymer 21.2
I got g. This carbobetaine-modified polymer is
90% of the acid anhydride groups in the intermediately modified polymer were modified, and the number average molecular weight was 2,500. This carbobetaine-modified polymer is referred to as antistatic agent D. Examples 5 to 8, Comparative Example 1 2 parts by weight of antistatic agent A was added to 100 parts by weight of powder obtained by mechanically crushing polypropylene (manufactured by Mitsui Petrochemical Industries, Ltd., trade name Mitsui Petrochemical Polypro J300).
After adding parts by weight and uniformly mixing with a Henschel mixer, pellets containing an antistatic agent were obtained through a pelletizing process (Example 5). Similarly, 3 parts by weight of antistatic agent B (Example 6), 3 parts by weight of antistatic agent C (Example 7), and 2.5 parts by weight of antistatic agent D (Example 8) were added to 100 parts by weight of powder. Pellets containing an antistatic agent were obtained. Then,
Using these four types of pellets, films were molded using an air-cooled inflation molding machine, and films 1 to 1 (containing 2 parts by weight of antistatic agent A (Example 5)) and films 2 to 2 were formed using an air-cooled inflation molding machine. Films containing 3 parts by weight of antistatic agent B (Example 6); Films 3 to 3 containing 3 parts by weight of antistatic agent C (Example 7); Films 4 to 2.5 parts by weight of antistatic agent D. Four types of films were obtained (Example 8). Films containing no antistatic agent were molded in the same manner as films 5 to 5 (Comparative Example 1).
After conditioning these films for 2 days at 25° C. and 60% RH, their surface resistivity values were measured using a surface resistivity meter manufactured by Takeda Riken. The results are shown in Table 1.

【table】

[Table] Example 9, Comparative Example 2 Polyethylene pellets [Mitsui Petrochemical Industries, Ltd.]
2 parts by weight of antistatic agent B was added to 100 parts by weight of the powder obtained by mechanically crushing ``HIZEX 5000S'', which was manufactured by HIZEX 5000S), and mixed in a Henschel mixer, and then subjected to a pelletizing process to form pellets containing the antistatic agent. I got it. Films 6 to 6 were then obtained from the pellets using an inflation molding machine (Example 9). In addition, polyethylene pellets (trade name: HIZEX 5000S) were molded in the same manner to obtain films 7 to 7 containing no antistatic agent. After these films were left in an atmosphere of 25° C. and 65% RH for 2 days, the surface resistivity values were measured. The results are shown in Table 2.

[Table] Examples 10 to 13, Comparative Examples 3 to 6 Commercially available charged Inhibitor 4
Seeds: lauryl betaine [Kao Atlas Co., Ltd.]
manufactured by Sanyo Kasei Co., Ltd., trade name Amhitol B (Comparative Example 3)], hydroxyethyl-sodiocarboxymethyl-alkylbetaine [manufactured by Sanyo Kasei Co., Ltd., trade name Chemistat 4700 (Comparative Example 4)], alkylbetaine [No.
[manufactured by Kogyo Seiyaku Co., Ltd., trade name Amogen K (Comparative Example 5)] and dimethylalkyl betaine [manufactured by Nihon Yushi Co., Ltd., trade name Anon BF (Comparative Example 6)] at 1.5% each.
Parts by weight were added, mixed uniformly in a Henschel mixer, and then subjected to a pelletizing process to form pellets.
Then, these pellets were made into a sheet using an extruder connected to a die, and further stretched 5 times in the machine direction and the width direction to form a biaxially stretched film (Comparative Examples 3 to 6). In addition, biaxially stretched films were formed in the same manner using the pellets containing the four types of antistatic agents obtained in Examples 5 to 8 (Examples 10 to 8).
13). These films were subjected to corona discharge treatment immediately after being molded, and the surface resistivity values were immediately measured. In addition, the surface resistivity was measured after aging for one week in an atmosphere of 40° C. and 80% RH. The results are shown in Table 3.

【table】

[Table] Examples 14 to 17, Comparative Examples 7 to 10 The biaxially stretched films formed in Examples 10 to 13 and Comparative Examples 3 to 6 were subjected to corona discharge treatment and those not subjected to corona discharge treatment. and make 25
The surface resistivity value was measured after being left in an atmosphere of 60% RH for 10 days. The results are shown in Table 4.

[Table] Comparative Examples 11 to 13, Examples 18 to 21 The corona-treated films obtained in Examples 10 to 13 and Comparative Examples 3 to 6 were treated with water and ethanol at 60°C, respectively. time and
The extraction operation was performed at 40°C for 1 hour. After the extraction operation was completed, the film was thoroughly washed with acetone and then dried under reduced pressure at room temperature overnight. These films were left in an atmosphere of 25° C. and 60% RH overnight, and then the surface resistivity values were measured. Table 5 shows the results.
It was shown to.

[Table] Comparative example 15 Polyethylene (number average molecular weight 85000w/
n4.0) and 2500 g of o-dichlorobenzene were charged into a glass reactor 1 equipped with a stirring blade and a cooling tube, and after purging the system with nitrogen, the temperature was raised to 165° C. with stirring. In this solution are 19.6 g of maleic anhydride and ditertiary butyl peroxide.
0.4 g was added dropwise over 4 hours, and the mixture was allowed to react for 2 hours. After the reaction was completed, the reaction mixture was post-treated in the same manner as in Example 4, and the maleic anhydride content was 1.33 mmol/g and the number average molecular weight was 96500.
56 g of intermediately modified polymer was obtained. Next, 20 g of this intermediate modified polymer and a carbobetaining agent [H ₂ NCH ₂ CH ₂ CH ₂ N(CH ₃ ) ₂ CH ₂ COO
] 13 g, paraxylene 800 c.c. and dimethyl sulfoxide 300 c.c. were charged into a glass reactor with a capacity of 1 equipped with a stirring blade and a cooling tube,
After purging the system with nitrogen, the temperature was raised to 140°C and the reaction was allowed to proceed for 7 hours. After the reaction was completed, the reaction mixture was worked up in the same manner as in Example 1 to obtain the formula The carbobetaine type functional group content expressed as
A carbobetaine-modified polymer of 0.65 mmol/g was obtained. This carbobetaine-modified polymer had 55% of the acid anhydride groups of the intermediately modified polymer modified and had a number average molecular weight of 106,500. 2 parts by weight of this polymer was added to 100 parts by weight of polypropylene powder (made by Mitsui Petrochemical Industries, Ltd., product name: Mitsui Petrochemical Polypro J300 pulverized) and mixed uniformly with a Henschel mixer, followed by a pretizing process. After that, it was made into pellets. Next, this pellet was made into a sheet using an extruder connected to a die, and further stretched 5 times in both the transverse and longitudinal directions, but film cracking occurred during stretching and a biaxially stretched film could not be obtained. .

Claims (1)

[Scope of Claims] 1. An unspecified carbon atom of an olefinic polymer base resin consisting of α-olefin component units having 2 to 6 carbon atoms is represented by the general formula [] and/or general formula [] (In formula [] and formula [], R ¹ represents an alkylene group having 1 to 3 carbon atoms, R ² represents a methylene group, R ³ and R ⁴ each represent an alkyl group having 1 to 2 carbon atoms, R ⁵ to R ⁶ each represent a hydrogen atom, R ₇ represents a hydrogen atom,
X represents an oxygen atom or >NH. ) is 0.05 to 0.25 per 100 g of the carbobetaine-modified olefin polymer.
A carbobetaine-modified olefin polymer which is grafted in molar equivalents (an average of 0.25 to 62.5 grafts per base resin molecule) and whose number average molecular weight is in the range of 500 to 25,000. 2. The carbobetaine-modified olefin polymer according to claim 1, wherein the base resin to which the carbobetaine-type functional group is bonded has a molecular weight distribution (w/n) in the range of 1.0 to 10. 3. The base resin to which the carbobetaine-type functional group is bonded has α of 2 to 6 carbon atoms constituting it.
- The carbobetaine-modified olefin polymer according to claim 1 or 2, which is an olefin polymer in which the content of olefin component units is in the range of 70 to 100 mol%. 4 An unspecified carbon atom of an olefin polymer base resin consisting of an α-olefin component unit having 2 to 6 carbon atoms is represented by the general formula [] and/or general formula [] (In formula [] and formula [], R ¹ represents an alkylene group having 1 to 3 carbon atoms, R ² represents a methylene group, R ³ and R ⁴ each represent an alkyl group having 1 to 2 carbon atoms, R ⁵ to R ⁶ each represent a hydrogen atom, R ⁷ represents a hydrogen atom,
X represents an oxygen atom or >NH. ) is 0.05 to 0.25 per 100 g of the carbobetaine-modified olefin polymer.
An antistatic agent comprising a carbobetaine-modified olefin polymer which is grafted in molar equivalents (an average of 0.25 to 62.5 grafts per base resin molecule) and whose number average molecular weight is in the range of 500 to 25,000. 5 Consisting of the carbobetaine-modified olefin polymer according to claim 1, wherein the molecular weight distribution (w/n) of the base resin to which the carbobetaine type functional group is bonded is in the range of 1.0 to 10. Antistatic agent. 6 The base resin to which the carbobetaine type functional group is bonded has a carbon number of 2 to 6,
- An antistatic agent comprising a carbobetaine-modified olefin polymer according to claim 4 or 5, which is an olefin polymer having a content of olefin component units in the range of 70 to 100 mol%.