JP4513576B2 - Modified polyolefin resin, method for producing the same, and adhesive modified polyolefin resin composition - Google Patents

Description

  The present invention relates to a method for producing a modified polyolefin resin having good adhesion to an adherend, less fish eyes and excellent appearance, at low cost, a modified polyolefin resin produced by this method, and this modified polyolefin resin. The present invention relates to an adhesive modified polyolefin resin composition.

  Polyolefin resins made of olefin homopolymers such as polyethylene and polypropylene and copolymers with other copolymerizable monomers based on these olefins are relatively inexpensive and have good moldability, Since it has characteristics such as heat resistance, solvent resistance, mechanical properties, and appearance, it is processed into various molded products and used in various fields. However, since these polyolefin resins are basically composed of saturated hydrocarbons, they have poor chemical reactivity and low polarity, and thus have problems in adhesion, paintability, printability, and the like.

  In order to solve this problem, a method of treating a polyolefin resin with radiation such as an electron beam or ozone, or an ethylenically unsaturated compound such as a vinyl compound or an unsaturated carboxylic acid in the presence of a radical generator such as an organic peroxide. A method of modifying a compound by graft reaction is known. Graft modification methods are roughly classified into a so-called solution method in which a polyolefin resin is reacted in a solution in a solvent and a so-called melting method in which reaction is performed by melt kneading using an extruder. Among these methods, the solution method is generally expensive because it uses a large amount of solvent, and has the disadvantages that it requires processing such as solvent recovery after production and environmental considerations. Has attracted attention as a simple and inexpensive method that does not require a solvent.

  However, in order to increase the modification rate by the melting method and sufficiently obtain the effect of improving the properties by modification, there is a problem that it is necessary to add more ethylenically unsaturated compounds and radical generators. In particular, an increase in the amount of radical generator added is undesirable because it increases side reactions such as cross-linking of polyolefins, thereby causing an increase in appearance, an increase in fish eyes, and deterioration of the resin.

  Therefore, in order to obtain a modified polyolefin resin having good adhesion and good appearance by the melting method, the addition amount and addition method of the ethylenically unsaturated compound, the radical generator, etc. are optimized, which is an undesirable side effect. It is necessary to carry out the grafting reaction while suppressing the reaction.

Conventionally, as a method for producing a modified polyolefin resin by a melting method,
(1) A method using a twin-screw extruder in which a base resin and a vinyl monomer are premixed and the ratio of the screw length (L) to the diameter (D) is 30 or more (Japanese Patent Laid-Open No. 8-109227) (Publication)
(2) A method in which one of a radical generator and an ethylenically unsaturated compound is added to polyolefin and melt-kneaded, and then the other of the radical generator and the ethylenically unsaturated compound is supplied (Japanese Patent No. 3258328)
However, all of these methods supply the ethylenically unsaturated compound and the radical generator all at once, so that the grafting efficiency is low and the increase in fish eyes cannot be remarkably suppressed.

Also,
(3) A method for improving the grafting efficiency of unsaturated carboxylic acid or its derivative using carbon dioxide as a reaction medium (Japanese Patent Laid-Open No. 2002-256042)
However, this method is not preferable because, as is apparent from the effect of Comparative Example 6 described later, the fish eye is increased at the same time as the grafting efficiency of the unsaturated carboxylic acid or its derivative is improved.

Furthermore,
(4) Using a twin screw extruder having two or more raw material supply ports, supplying a base resin from the first raw material supply port, supplying a radical generator from the first raw material supply port or the second raw material supply port, A method of performing modification by supplying an unsaturated carboxylic acid or its anhydride from a supply port after the second raw material supply port (Japanese Patent Laid-Open No. 2002-187914)
In this method, as is apparent from the effect of Comparative Example 5 described later, since the unsaturated carboxylic acid or its anhydride and the base resin are not sufficiently mixed, the screw and barrel Unsaturated carboxylic acid aggregates that cause corrosion are likely to occur, which is not preferable.
JP-A-8-109227 Japanese Patent No. 3258328 JP 2002-256042 A JP 2002-187914 A

  An object of the present invention is to provide a modified polyolefin resin having good adhesion to an adherend, few fish eyes and excellent appearance, at low cost.

  The inventors of the present invention have made extensive studies in order to produce a modified polyolefin resin having good adhesion to the adherend, little fish eye and excellent appearance, and as a result, the polyolefin resin is present in the presence of a radical generator. Below, when modifying with an unsaturated carboxylic acid and / or derivative thereof by a melting method, using an extruder having two or more raw material supply ports, supplying a radical generator from two or more raw material supply ports, In order to complete the present invention, it has been found that the occurrence of fish eyes can be greatly suppressed by reacting a polyolefin resin as a base resin with an unsaturated carboxylic acid and / or a derivative thereof stepwise in an extruder. It came.

That is, the gist of the present invention resides in the following method for producing a modified polyolefin resin.
[1] having two or more raw material supply ports in which (A) a polyolefin resin, (B) an unsaturated carboxylic acid and / or derivative thereof, and (C) a radical generator are arranged in different positions in the extrusion direction In a method for producing a modified polyolefin resin by feeding (C) an unsaturated carboxylic acid and / or a derivative thereof to (A) a polyolefin resin in the presence of a radical generator (C) in the presence of a radical generator, (C) ) Supplying polyolefin resin and (B) unsaturated carboxylic acid and / or derivative thereof from the first raw material supply port on the most upstream side of the extruder, and (C) two or more raw material supply ports for the radical generator. A process for producing a modified polyolefin resin, characterized by being supplied from

[2] In the modified polyolefin resin according to [1], (C) a radical generator is supplied from at least the first raw material supply port and the second second raw material supply port from the upstream side of the extruder. Production method.

[3] The modified polyolefin according to [1], wherein (C) the radical generator is supplied from at least a second second raw material supply port and a third third raw material supply port from the upstream side of the extruder. Manufacturing method of resin.

[4] In [1] to [3], when supplying the (C) radical generator from n (n ≧ 2) raw material supply ports, the most upstream raw material among the n raw material supply ports A method for producing a modified polyolefin resin, characterized in that the supply amount of the radical generator supplied from the supply port is less than 1 / (n-1) of the total supply amount of the (C) radical generator to the extruder. .

[5] In [1] to [4], the extruder is a twin-screw extruder having at least the same number of reaction kneading parts as the raw material supply ports on the downstream side of the respective raw material supply ports. (A) Addition of unsaturated carboxylic acid and / or derivative thereof to (A) polyolefin resin by melt-kneading the polyolefin resin at a temperature of 180 to 270 ° C., and (A) retention of polyolefin resin in the extruder A process for producing a modified polyolefin resin, characterized in that the melt extrusion is carried out with the time being at least three times the 99.9% decomposition time of the (C) radical generator at the resin temperature.

[6] In [1] to [5], the raw material supply port to which the (C) radical generator is supplied, the raw material supply port after the second second raw material supply port from the upstream side of the extruder (D) Carbon dioxide gas and / or nitrogen gas is supplied from (D) Unsaturated carboxylic acid and / or its derivative is added to (A) polyolefin resin in the presence of carbon dioxide gas and / or nitrogen gas. And then, carbon dioxide gas and / or nitrogen gas is separated from the vent port.

  Another gist of the present invention resides in a modified polyolefin resin produced by such a method for producing a modified polyolefin resin.

  Yet another subject matter of the present invention is an adhesive modified polyolefin resin composition comprising the modified polyolefin resin and an unmodified polyolefin resin, wherein the weight ratio of the modified polyolefin resin to the unmodified polyolefin resin is 1 : Adhesive modified polyolefin resin composition characterized by being in the range of 99 to 99: 1.

  According to the present invention, in graft modification of a polyolefin resin by a melting method, (C) a radical generator is supplied from two or more raw material supply ports, and (A) a polyolefin resin as a base resin and (B) unsaturated By causing the carboxylic acid and / or its derivative to react stepwise in the extruder, the generation of fish eyes can be significantly suppressed. Therefore, it is possible to provide a modified polyolefin resin having good adhesion to the adherend, little fish eye, and excellent appearance, at low cost.

(C) Specifically, the radical generator is
(1) First raw material supply port and second raw material supply port (Claim 2)
Or
(2) Second raw material supply port and third raw material supply port (Claim 3)
It is preferable to supply
(3) You may supply to a 1st raw material supply port, a 2nd raw material supply port, and a 3rd raw material supply port.

  In the present invention, when supplying (C) the radical generator from n (n ≧ 2) raw material supply ports, the radical supplied from the most upstream raw material supply port among the n raw material supply ports. It is preferable that the supply amount of the generator is less than 1 / (n-1) of the total supply amount of the (C) radical generator to the extruder.

  Moreover, in this invention, the temperature of (A) polyolefin resin in each reaction kneading part is 180-270 using the twin screw extruder which has at least the same number of reaction kneading parts as a raw material supply port in the downstream of each raw material supply port. (B) Unsaturated carboxylic acid and / or derivative thereof is added to (A) polyolefin resin by melt kneading at 0 ° C., and (A) residence time of the polyolefin resin in the extruder is (C) at the resin temperature. It is preferable to melt-extrusion at 3 times or more of the 99.9% decomposition time of the radical generator (Claim 5).

  Further, in the present invention, (C) a raw material supply port to which a radical generator is supplied, (D) carbon dioxide gas and / or nitrogen gas is supplied from a raw material supply port after the second raw material supply port, and (D ) After adding (B) unsaturated carboxylic acid and / or its derivative to (A) polyolefin resin in the presence of carbon dioxide and / or nitrogen gas, carbon dioxide and / or nitrogen gas is separated from the vent port. Thus, a high-quality modified polyolefin resin can be obtained, which is preferable.

  Hereinafter, embodiments of the modified polyolefin resin of the present invention, a method for producing the same, and an adhesive modified polyolefin resin composition will be described in detail.

[(A) Polyolefin resin]
Examples of the polyolefin resin used in the present invention include ethylene, propylene, butene-1, hexene-1, 3-methylbutene-1, 4-methylpentene-1, and heptene- produced using a Ziegler catalyst or a metallocene catalyst. 1, a homopolymer of an α-olefin having 2 to 20 carbon atoms, such as octene-1 and decene-1, a random copolymer of two or more monomers selected from these α-olefins, or a block Copolymer or the above-mentioned α-olefin, vinyl acetate, (meth) acrylic acid [Here, “(meth) acryl” means acryl and methacryl. , Copolymers with (meth) acrylic acid esters, etc., specifically, ethylene homopolymers such as low, medium and high density polyethylene (branched or linear), ethylene-propylene copolymers, etc. Polymer, ethylene-1-butene copolymer, ethylene-propylene-1-butene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-1-hexene copolymer, ethylene-1-heptene Copolymer, ethylene-1-octene copolymer, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid methyl copolymer, ethylene- (meth) acrylic Ethylene resins such as ethyl acid copolymer, ethylene- (meth) acrylic acid-methyl (meth) acrylate copolymer, and ethylene-propylene copolymer, ethylene - propylene - non-conjugated diene copolymer, ethylene-1-butene copolymer, ethylene-1-butene - ethylene-based rubber such as non-conjugated diene copolymers. The polyolefin resin may be a mixture of these polymers and / or copolymers. Among them, in the present invention, a polyolefin resin such as a branched low density ethylene homopolymer or a linear low density ethylene-α-olefin copolymer is preferable.

The ethylene polymer preferably has a density of 0.850 to 0.950 g / cm ³ , and a melt flow rate measured at a temperature of 190 ° C. and a load of 21.18 N in accordance with JIS K7210 is 0.01. The thing of -200g / 10min is preferable, and the thing of 0.1-100g / 10min is especially preferable.

The ethylene-α-olefin copolymer has 6 to 12 carbon atoms such as ethylene and 1-hexene, 4-methyl-1-hexene, 1-heptene, 1-octene and 1-decene. A linear ethylene-α-olefin copolymer comprising an α-olefin, having a density of 0.850 to 0.915 g / cm ³ and a melt flow rate of 0.01 to 50 g / 10 min under the same conditions as above. preferable.

  In the present invention, a molecular weight distribution and a crystallization distribution are narrower than a polyolefin resin produced using a conventionally used Ziegler-based catalyst, and it has a more uniform composition distribution. Therefore, it is produced using a metallocene catalyst. The polyolefin resin is preferably used.

[(B) Unsaturated carboxylic acid and / or derivative thereof]
Examples of the unsaturated carboxylic acid and / or derivative thereof used in the present invention include unsaturated carboxylic acids such as (meth) acrylic acid, crotonic acid, isocrotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, and tetrahydrophthalic acid. Examples thereof include one or more acids or anhydrides thereof. Among them, unsaturated dicarboxylic acid or anhydride thereof, particularly maleic acid or anhydride thereof, particularly maleic anhydride is preferable from the viewpoint of reactivity.

  The amount of the unsaturated carboxylic acid and / or derivative thereof added in the graft modification is preferably 0.2 to 7.0 parts by weight with respect to 100 parts by weight of the polyolefin resin, and 0.5 to 5.0 parts by weight. Is more preferable. When the added amount of the unsaturated carboxylic acid and / or derivative thereof is less than 0.2 parts by weight, the amount of the unsaturated carboxylic acid grafted onto the polyolefin resin is reduced, so that a modified polyolefin resin having sufficient adhesiveness is obtained. It becomes difficult to obtain. On the other hand, addition of an amount exceeding 7.0 parts by weight is not preferable because a decrease in adhesion performance due to an increase in unreacted components occurs.

[(C) Radical generator]
Examples of the radical generator used in the present invention include organic peroxides. As the organic peroxide, an organic compound having a half-life of 1 minute (one-minute half-life temperature) in the range of 150 to 200 ° C. from the viewpoint of the addition reactivity of the unsaturated carboxylic acid or its anhydride to the polyolefin resin. Peroxides are preferred. Specifically, for example, di-t-butyl peroxide (1 minute half-life temperature 193 ° C.), t-butyl cumyl peroxide (178 ° C.), dicumyl peroxide (171 ° C.) ), 2,5-dimethyl-2,5-di (t-butylperoxy) hexane (179 ° C.), 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3 (same as above) 193 ° C.), dialkyl peroxides, t-butyl peroxyacetate (159 ° C.), t-butyl peroxylaurate (165 ° C.), t-butyl peroxybenzoe (166 ° C), di-t-butyldiperoxyphthalate (159 ° C), t-butylperoxyisopropyl carbonate (158 ° C), 2,5-dimethyl-2,5-di (benzoylperoxy) ) Peroxyesters such as hexane (162 ° C.), 2,5-dimethyl-2,5-di (benzoylperoxy) hexyne-3 (162 ° C.), methyl ethyl ketone peroxide (171 ° C.), cyclohexanone peroxy ester Ketone peroxides such as oxide (at 174 ° C.), preferably dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, di-t-butyl peroxide, 2 , 5-dimethyl-2,5-di (t-butylperoxy) hexyne 3 and the like. These may be used alone or in combination of two or more.

  The amount of radical generator added in graft modification is preferably 0.005 to 1 part by weight, more preferably 0.02 to 0.5 part by weight, based on 100 parts by weight of the polyolefin resin. If the amount of radical generator added is less than 0.005 parts by weight, the amount of unsaturated carboxylic acid grafted onto the polyolefin resin will be small, and it will be difficult to obtain a modified polyolefin resin having sufficient adhesion. On the other hand, addition of an amount exceeding 1 part by weight is not preferable because side reactions such as degradation and crosslinking of the polyolefin resin increase, resulting in deterioration of adhesiveness and deterioration of appearance.

[Extruder]
In the present invention, the extruder used for melt kneading of the raw material may be any one having two or more raw material supply ports with different arrangement positions in the extrusion direction, such as a single-screw extruder or a multi-screw extruder. Although a continuous extruder can be used, it is preferable to use a multi-screw extruder, particularly a twin-screw extruder, in view of a high degree of freedom in process design.

  The screw of the extruder must have at least the same number of reaction kneading parts as the raw material supply ports. In addition to the reaction kneading part, a separate kneading part is added for the purpose of improving the dispersibility of the raw material, for example. Also good.

  A normally used twin-screw extruder is a barrel equipped with a raw material supply port, a vent port, and a jacket, and is arranged in the inside, and a plurality of grooves are engraved on the surface and rotate in the same direction or in different directions. And a reaction kneading part constituted by a plurality of kneading disks are provided in the form of meshing with each other or in the form of non-meshing with each other. ing. As a twin screw extruder having a high kneading function, for example, the “TEXα” series is commercially available from Nippon Steel Works, and the “TEM-SS” series is available from Toshiba Machine Co., Ltd.

  The extruder used in the present invention has two or more raw material supply ports with different arrangement positions in the extrusion direction, and the ratio (L / D) of the screw length (L) to the screw diameter (D) is 10 to 10. 100, the rotational direction is the same direction, and the meshing form is partial or fully meshed. As the screw configuration of the reaction kneading section, any configuration may be used as long as a suitable resin temperature and residence time described later can be ensured. (B) Unsaturated carboxylic acid and / or derivative thereof and (C) radical In view of dispersibility of the generator (A) in the polyolefin resin and residence time, the generator is preferably composed of a combination of a plurality of kneading disks.

[Method for producing modified polyolefin resin]
<Supply of raw materials>
The method for producing the modified polyolefin resin of the present invention comprises the above-mentioned (A) polyolefin resin, (B) unsaturated carboxylic acid and / or derivative thereof, and (C) radical generator as raw materials. Thus, it is supplied to an extruder having two or more raw material supply ports whose arrangement positions are different in the extrusion direction, and (C) in the presence of a radical generator, (A) a polyolefin resin is added to (B) an unsaturated carboxylic acid and / or Or a derivative reaction thereof, wherein (A) a polyolefin resin and (B) an unsaturated carboxylic acid and / or a derivative thereof are used as a first raw material at the most upstream side of the extruder. (C) A radical generator is supplied from two or more raw material supply ports.

  In the present invention, (B) the unsaturated carboxylic acid and / or derivative thereof must be supplied to (A) the polyolefin resin simultaneously with (C) supply of the radical generator or at least before supply of (C) radical generator. There is. Accordingly, (B) the unsaturated carboxylic acid and / or derivative thereof is supplied from the first raw material supply port together with (A) the polyolefin resin. In addition, although (B) unsaturated carboxylic acid and / or its derivative can supply only a part of required amount from a 1st raw material supply port, the remainder can also be supplied from the raw material supply port after a 2nd raw material supply port. In the present invention, (A) the polyolefin resin and (B) the unsaturated carboxylic acid and / or derivative thereof are sufficiently kneaded to cause corrosion of the screw or barrel (B) the unsaturated carboxylic acid and / or Alternatively, in order to prevent the formation of aggregates of the derivatives, it is preferable to supply the total necessary amount of (A) the polyolefin resin and (B) the unsaturated carboxylic acid and / or the derivative thereof from the first raw material supply port.

  In the present invention, (C) the radical generator is dividedly supplied at at least two raw material supply ports after the first raw material supply port. Since the (C) radical generator that is dividedly supplied at two or more raw material supply ports is intermittently supplied, problems such as a decrease in graft efficiency and non-uniformity of the reaction occur, and therefore it is preferable to supply continuously.

  The supply amount to each raw material supply port is as follows: (C) When supplying the radical generator from n (n ≧ 2) raw material supply ports, the most upstream raw material among the n raw material supply ports The supply amount of the (C) radical generator supplied from the supply port is less than 1 / (n-1) of the total supply amount of the (C) radical generator to the extruder, particularly 1 / 2n to 1 / n. It is preferable to do. When the supply amount of the (C) radical generator supplied from the most upstream raw material supply port is too large, the effect of suppressing fish eye generation by the divided supply of the (C) radical generator according to the present invention can be sufficiently obtained. Can not. On the other hand, if the amount is too small, the graft amount and graft efficiency of the unsaturated carboxylic acid (A) onto the polyolefin resin are lowered. More preferably, the amount of the (C) radical generator supplied from each raw material supply port is preferably approximately the same in order to uniformly perform a stepwise graft reaction and prevent fish eyes.

In the present invention, specific methods for supplying raw materials to the extruder include, for example, the following methods, but are not limited to the following methods.
(1) Using an extruder having raw material supply ports at two locations, the required amount of (A) polyolefin resin, (B) unsaturated carboxylic acid and / or derivative thereof and (C) radical generation from the first raw material supply port Of supplying a half of the required amount of the agent and supplying the remaining half of the (C) radical generator from the second raw material supply port
(2) Using an extruder having raw material supply ports at three locations, the necessary amount of (A) polyolefin resin, (B) unsaturated carboxylic acid and / or derivative thereof is supplied from the first raw material supply port, , A method of supplying a half of the required amount of the (C) radical generator from the third raw material supply port
(3) Using an extruder having raw material supply ports at three locations, the required amount of (A) polyolefin resin, (B) unsaturated carboxylic acid and / or derivative thereof and (C) generation of radicals from the first raw material supply port Supply of 1/3 of the required amount of the agent, and supplying 1/3 of the required amount of (C) radical generator from the second and third raw material supply ports, respectively

<Resin temperature and residence time>
In the present invention, using a twin screw extruder having at least the same number of reaction kneading parts as the raw material supply ports on the downstream side of each raw material supply port, the temperature of (A) polyolefin resin in each reaction kneading part is set to 180 to 270 ° C. By melt kneading, (B) the unsaturated carboxylic acid and / or derivative thereof is added to (A) the polyolefin resin, and (A) the residence time of the polyolefin resin in the extruder is changed to (C) radical generation at the resin temperature. It is preferable to melt-extrusion at 3 times or more of the 99.9% decomposition time of the agent.

  If the resin temperature is less than 180 ° C., sufficient graft reaction efficiency cannot be obtained, and if it exceeds 270 ° C., the resin is deteriorated, burnt, decomposed, etc. due to the high temperature.

  Further, if the residence time in the extruder of (A) polyolefin resin is less than 3 times the 99.9% decomposition time of the (C) radical generator at the resin temperature, the reaction becomes inadequate, Increase or decrease in adhesion. If this residence time is excessively long, deterioration of the polyolefin resin and side reactions increase and appearance defects such as increase of fish eyes occur. Therefore, the residence time in the extruder of (A) polyolefin resin is It is preferably 100 times or less, particularly 3 to 10 times the 99.9% decomposition time of the (C) radical generator at temperature. Hereinafter, the ratio of the residence time of the (A) polyolefin resin in the extruder to the 99.9% decomposition time of the (C) radical generator at the resin temperature is referred to as “residence time / 99.9% decomposition time”.

<Supply of reaction medium>
In the present invention, (D) carbon dioxide gas and / or nitrogen gas is supplied as a reaction medium to the reaction kneading section in the extruder, and (B) unsaturated carboxylic acid and / or its derivative is added to (A) polyolefin resin. In order to improve the reaction efficiency and reaction uniformity, reduce unreacted components, and obtain a high-quality modified polyolefin resin after separating the carbon dioxide gas and / or nitrogen gas from the vent port of the extruder Is preferable.

  (D) The reason why the reaction efficiency and the reaction uniformity are improved by supplying carbon dioxide gas and / or nitrogen gas is that (D) carbon dioxide gas and / or nitrogen gas is used as a reaction medium, and (A) in the polyolefin resin By rapidly dissolving and diffusing at the molecular level, swelling the resin and reducing the number of entanglements, the contact probability between the reactive site of the resin and (B) the unsaturated carboxylic acid and / or its derivative is increased and uniformized. It is possible that Moreover, as a reason for reducing unreacted components, when carbon dioxide gas and / or nitrogen gas is degassed after modification, carbon dioxide gas and / or nitrogen gas impregnated in the modified polyolefin resin serves as an extractant, It is considered that impurities such as unreacted components are efficiently removed together with carbon dioxide gas and / or nitrogen gas.

  Here, the supply method of (D) carbon dioxide gas and / or nitrogen gas is not particularly limited, and a known method can be employed. For example, a method of supplying in a gas state by controlling the pressure of a supply unit from a cylinder through a pressure reducing valve, a method of controlling a flow rate from a cylinder through a metering pump, and supplying in a liquid state or a supercritical state, etc. It is done. Among these, there is a method of supplying in a liquid state or a supercritical state.

  The carbon dioxide gas and / or nitrogen gas is preferably supplied to the reaction kneading section. Therefore, (A) the polyolefin resin and (B) the unsaturated carboxylic acid and / or derivative thereof supplied from the first raw material supply port are (C) It is preferable to supply from the raw material supply port downstream of the raw material supply port to which (C) the radical generator is supplied, which is a reaction kneading unit kneaded in the presence of the radical generator. Therefore, for example, when the (C) radical generator is supplied at the first raw material supply port and the second raw material supply port and thereafter, the carbon dioxide gas and / or nitrogen gas is supplied from the second raw material supply port and thereafter. It is preferable to supply to the raw material supply port. Further, the carbon dioxide gas and / or the nitrogen gas is more preferably dividedly supplied at the same number of raw material supply ports as the reaction kneading section in order to improve reaction efficiency and reaction uniformity.

  (D) The supply amount of carbon dioxide gas and / or nitrogen gas is preferably 0.1 to 10 parts by weight, particularly 0.5 to 5 parts by weight, based on 100 parts by weight of (A) polyolefin resin. (D) If the supply amount of carbon dioxide gas and / or nitrogen gas is less than this range, the above-mentioned effect due to the supply cannot be sufficiently obtained. It will not progress. Furthermore, it becomes difficult to separate the gases.

  (D) When carbon dioxide gas and / or nitrogen gas is supplied at a plurality of locations, the amount supplied to each raw material supply port is (D) carbon dioxide gas and / or nitrogen gas as in the case of (C) radical generator. When supplying from the raw material supply port of (n ≧ 2), among the n raw material supply ports, the supply amount of (D) carbon dioxide gas and / or nitrogen gas supplied from the most upstream raw material supply port, (D) Less than 1 / (n-1) of the total amount of carbon dioxide gas and / or nitrogen gas supplied to the extruder, particularly 1 / (n-1) to 1 / n. If the supply amount of (D) carbon dioxide gas and / or nitrogen gas supplied from the most upstream raw material supply port is too large, the temperature of the reaction section will be too low and the reaction will not proceed. Furthermore, it becomes difficult to separate the gases. On the other hand, if the amount is too small, (D) the above-mentioned effect by the divided supply of carbon dioxide gas and / or nitrogen gas according to the present invention cannot be sufficiently obtained.

<Other additives>
In the production process of the modified polyolefin resin, various additives other than (A) a polyolefin resin, (B) an unsaturated carboxylic acid and / or derivative thereof, and (C) a radical generator, as long as the effects of the present invention are not impaired. Can be used. Examples of additives that can be used here include antioxidants, ultraviolet absorbers, lubricants, colorants, foaming agents, fillers, conductive agents, antistatic agents, antifogging agents, metal deactivators, and dispersants. Flame retardants, processing aids, mold release agents, bactericides, fungicides, molecular weight modifiers, and the like.

<Removal of reaction by-products and unreacted products>
Unreacted (B) unsaturated carboxylic acid and / or its derivative contained in the graft reaction product, (C) decomposition product of radical generator, etc. not only serve as an adhesion inhibitor, but also cause odor and hue deterioration. It is preferable to remove it because it also causes. As a method of removing the unreacted components and decomposition products,
(1) Method of removing by suction from the vent port provided in the extruder
(2) A method in which water is dispersed in the molten resin in the extruder and then sucked and removed together with water from the vent port provided in the extruder.
(3) A method of performing a deodorization treatment such as a hopper dryer treatment immediately after pelletizing the graft reaction product is preferably used.

[Modified polyolefin resin]
The modified polyolefin resin according to the present invention thus produced preferably has a melt flow rate of 0.1 to 100 (g / 10 minutes). When the melt flow rate is out of this range, dispersibility with other resins, processability, and appearance may be deteriorated.

  The modified polyolefin resin preferably has a ratio of melt flow rate to the polyolefin resin before modification in the range of 0.05 to 1.0, and the amount of unsaturated carboxylic acid modification is 0.5 to 5. It is preferably 0% by weight, particularly 1.5 to 3.5% by weight, and the number of fish eyes is 80 or less.

[Adhesive modified polyolefin resin composition]
The adhesive modified polyolefin resin composition of the present invention is a composition containing the modified polyolefin resin thus produced and an unmodified polyolefin resin. Here, the weight ratio of the modified polyolefin resin to the unmodified polyolefin resin is preferably in the range of 1:99 to 99: 1, particularly preferably in the range of 3:97 to 20:80, especially 5 : It is preferable that it exists in the range of 95-10: 90.

  If the proportion of the modified polyolefin resin is less than this range, the effect of improving the adhesiveness by blending the modified polyolefin resin cannot be sufficiently obtained, and if too large, the cost is low by blending the unmodified polyolefin resin. A sufficient adhesive modified polyolefin resin composition cannot be obtained.

  The unmodified polyolefin resin to be blended with the modified polyolefin resin includes the above-mentioned polyolefin resin, and the polyolefin resin may be a raw material-modified polyolefin resin before the modification of the modified polyolefin resin. May be other different polyolefin resins.

  The adhesive modified polyolefin resin composition of the present invention may contain two or more modified polyolefin resins according to the present invention, or may contain two or more unmodified polyolefin resins.

  In addition, the adhesive-modified polyolefin resin composition of the present invention includes other thermoplastic resins and rubbers, antioxidants, ultraviolet absorbers, lubricants, colorants, and foaming agents as long as the effects of the present invention are not impaired. Including additives such as fillers, conductive agents, antistatic agents, antifogging agents, metal deactivators, dispersants, flame retardants, processing aids, mold release agents, bactericides, fungicides, molecular weight modifiers, etc. You can leave.

  In the production of the adhesive modified polyolefin resin composition of the present invention, modified polyolefin resin and unmodified polyolefin resin, and other resins, rubbers, additives, etc. used as necessary are usually tumbler blender, ribbon blender, V After being uniformly mixed by a mold blender, a Henschel mixer or the like, the mixture is melt-kneaded by a twin screw extruder and then pelletized.

  Such an adhesive-modified polyolefin resin composition of the present invention is usually obtained by sequential extrusion lamination, sandwich extrusion lamination, coextrusion on an adherend through or without an anchor coating agent by a conventionally known method. It is suitably used as a laminate by a laminating method, a method of co-extrusion together with an adherent resin, a method of preliminarily forming a film and thermally fusing the adherend resin.

  Examples of the adherend include various thermoplastic resins such as polyamide resin, polyester resin, saponified ethylene-vinyl acetate copolymer, polycarbonate resin, polystyrene resin, acrylic resin, and polyolefin resin. And metal foils such as aluminum, copper, lead, and stainless steel, plates, and paper.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely using an Example, this invention is not limited by a following example, unless the summary is exceeded.

In addition, the measurement method thru | or evaluation method of the physical-property value used by this invention are as follows.
(1) Screw state After modification for 2 hours, the screw of the extruder was taken out and the kneading part was visually observed and evaluated according to the following criteria.
○: No change in the kneading part Δ: Discoloration and rust are confirmed in the kneading part ×: Discoloration and rust are confirmed in the kneading part in addition to rust (dents, scratches, holes, etc.)

(2) Melt flow rate (MFR)
Measurement was performed under the conditions of a temperature of 190 ° C., a load of 2.16 kg (21.18 N), and an orifice diameter of 2.1 mm, and a melt flow rate (MFR, g / 10 minutes) was obtained.

(3) Unsaturated Carboxylic Acid Modification A pellet-like modified polyolefin resin was dissolved in boiling xylene, reprecipitated in acetone, and then vacuum dried at 80 ° C. for 6 hours to obtain a powdery sample. From the infrared absorption spectrum (absorption intensity of the carbonyl group) around 1780 cm ^{−1 of} the film obtained by press molding this sample, the amount of unsaturated carboxylic acid modification in the pellet was determined using a separately prepared calibration curve. .

(4) Number of fish eyes After a film of 30 μm thickness is air-cooled and blown from a modified polyolefin resin pellet under conditions of a molding temperature of 190 ° C. and a blow ratio of 1.4, a table-type film inspection device (Mamiya Oppy Co., Ltd.) The number of fish eyes with a diameter of 0.1 mm or more existing in an area of length × width = 12 cm × 20 cm was measured using “GX70LT”), and the measured value was divided by the film weight corresponding to the measurement area. The number of fish eyes was determined.

(5) Adhesive strength to EVOH Adhesive-modified polyolefin resin composition is used as an outer layer, and the inner layer is a saponified ethylene-vinyl acetate copolymer (EVOH: “F101A” manufactured by Kuraray Co., Ltd.). A coextruded blown film was produced. In addition, an extruder caliber, a layer structure ratio, and a laminated body formation speed are as follows.
(Extruder diameter)
Adhesive modified polyolefin resin composition / EVOH = 40 mmφ / 40 mmφ
(Layer composition ratio)
Outer layer / inner layer = 1/1 (total thickness = 60 μm)
(Laminate forming speed)
30m / min, 70m / min

  Using a strip-shaped sample cut out to a width of 10 mm from the obtained laminate, in accordance with JIS K6854, the inner layer (EVOH) at one end and the outer layer (modified polyolefin resin composition layer) are slightly peeled off in advance. Then, a T-shaped peel test was performed at a peel rate of 300 mm / min in an atmosphere at 23 ° C. to measure the peel strength, and this value was defined as the adhesive strength.

In the following Examples and Comparative Examples, (A) polyolefin resin, (B) unsaturated carboxylic acid and / or derivative thereof, and (C) radical generator were used as follows.
(A) Polyolefin resin A-1: A copolymer of ethylene, 1-hexene and propylene with a metallocene catalyst.
The melt flow rate at 190 ° C. is 16 g / 10 minutes, and the density is 0.89.
8 g / cm ³ linear ethylene-1-hexene-propylene copolymer A-2: a copolymer of ethylene, 1-hexene and propylene with a metallocene catalyst
A linear ethylene-1-hexene-propylene copolymer having a melt flow rate at 190 ° C. of 50 g / 10 min and a density of 0.880 g / cm ³ A-3: of ethylene and 1-butene A Ziegler-based copolymer comprising 190
A straight chain having a melt flow rate of 2 ° C / 10 min and a density of 0.920 g / cm ³
Ethylene-1-butene copolymer (B) unsaturated carboxylic acid and / or derivative thereof B: maleic anhydride (C) radical generator C: 2,5-dimethyl-2,5-di (tert-butylper) Oxy) hexane (Nippon Yushi Co., Ltd., trade name "Perhexa 25B")

In the following Examples and Comparative Examples, the twin screw extruder used for the production of the modified polyolefin resin is as follows.
Twin screw extruder I: Raw material supply ports and reaction kneading sections are provided at two locations in the raw material extrusion direction.
30mm diameter twin screw extruder (L / D = 52.5, rotating direction = same direction
Direction, meshing form = complete)
Twin screw extruder II: Raw material supply ports and reaction kneading sections are provided at three locations in the raw material extrusion direction.
30mm diameter twin screw extruder (L / D = 52.5, rotating direction = same direction
Direction, meshing form = complete)

Examples 1-3
(A) Polyolefin resin, (B) Unsaturated carboxylic acid and / or derivative thereof, (C) Radical generator is uniformly mixed with a Henschel mixer in the formulation shown in Table 1, and then the first raw material of twin-screw extruder I The mixture is supplied to the supply port, and further supplied with the amount of (C) radical generator shown in Table 1 from the second raw material supply port, and melt-kneaded at 230 ° C. for 2 hours and extruded into a strand (residence time / 99.99. 9% decomposition time = 7 times), and after pelletization, a hopper dryer was used for drying treatment at 60 ° C. for 15 hours to obtain a modified polyolefin resin. After the modification, the screw was taken out and the screw condition was examined. The results are shown in Table 1.

  Table 1 shows the melt flow rate, unsaturated carboxylic acid modification amount, and fisheye evaluation results of the resulting modified polyolefin resin.

  After 10% by weight of the modified polyolefin resin and 90% by weight of the polyolefin resin A-3 are uniformly mixed with a Henschel mixer, they are supplied to a single screw extruder having a diameter of 40 mm and melt kneaded at 190 ° C. to form a strand. Extrusion and pelletization gave an adhesive modified polyolefin resin composition.

  Table 1 shows the evaluation results of the adhesion strength to EVOH of this adhesive-modified polyolefin resin composition.

Example 4
Modification was performed in the same manner as in Examples 1 to 3 except that the twin screw extruder II was used as the twin screw extruder and the raw material supply amounts from the first, second and third raw material supply ports were changed to the amounts shown in Table 1. A polyolefin resin was produced and evaluated in the same manner, and the results are shown in Table 1.

Examples 5 and 6
In Examples 2 and 3, the twin screw extruder II was used as the twin screw extruder, and carbon dioxide gas increased to 10 MPa at 23 ° C. was used at the ratio shown in Table 1 at the second and third raw material supply ports. After addition, carbon dioxide was separated from the vent, and then extruded into strands and pelletized to produce modified polyolefin resins, evaluated in the same manner, and the results are shown in Table 1.

Comparative Examples 1-4
In Examples 1 to 4, the total amount of (C) radical generator was uniformly mixed with (A) polyolefin resin and (B) unsaturated carboxylic acid and / or derivative thereof in a Henschel mixer, and the first of the twin-screw extruder was used. A modified polyolefin resin was produced in the same manner except that it was supplied to the raw material supply port, and the evaluation was made in the same manner. The results are shown in Table 1.

Comparative Example 5
In Example 3, the first raw material supply port was supplied with a partial mixture of (A) polyolefin resin and (C) radical generator, and (B) the unsaturated carboxylic acid and / or derivative thereof was not supplied. (2) A modified polyolefin resin is produced in the same manner except that (B) the unsaturated carboxylic acid and / or derivative thereof and the remainder of the (C) radical generator are supplied to the raw material supply port, and the results are evaluated in the same manner. It is shown in Table 1.

Comparative Example 6
In Comparative Example 2, carbon dioxide gas increased to 10 MPa at 23 ° C. at the rate shown in Table 1 was added to the second raw material supply port with a pump, melted and kneaded at 230 ° C. for 2 hours, and then carbon dioxide gas was separated from the vent port. Then, a modified polyolefin resin was produced in the same manner except that it was extruded into a strand shape and pelletized, and evaluated in the same manner. The results are shown in Table 1.

  From Table 1, the following is clear.

  That is, the modified polyolefin resins according to the present invention (Examples 1 to 4) obtained by performing the modification by dividing and supplying the first raw material supply port and the second raw material supply port of the radical generator extruder have the same amount. Compared with the modified polyolefin resin (Comparative Examples 1 to 4) obtained by using the maleic anhydride and the radical generator and supplying the entire amount of the radical generator to the first raw material supply port for modification. The amount of carboxylic acid modification is increased, and the amount of fish eye generation is greatly reduced. In order to obtain a modified amount equivalent to that of the modified polyolefin resin according to the present invention (Examples 1 to 4) according to the conventional method in which the entire amount of the radical generator is supplied to the first raw material supply port, maleic anhydride and radical generator Since it is necessary to further increase the amount of addition, an increase in the amount of unreacted maleic anhydride, a cross-linking reaction between polyethylenes by a radical generator, and an increase in fish eyes become remarkable and the appearance is further deteriorated (Comparative Examples 1 to 2). 4).

  Moreover, when maleic anhydride is added from the supply port after the 2nd raw material supply port, corrosion of a screw is remarkable (Comparative Example 5). This is presumably because male acid aggregates that cause screw corrosion are generated because the base resin and maleic anhydride are not sufficiently dispersed.

  Moreover, the adhesive modified polyolefin resin composition (Examples 1-4) which mix | blended the modified polyolefin resin by this invention method is compared with the adhesive modified polyolefin resin composition (Comparative Examples 1-6) by a conventional method. The EVOH adhesive strength is excellent, and the superiority remarkably appears especially when the molding speed is high.

  The modified polyolefin resins obtained by adding carbon dioxide (Examples 5 and 6) were modified polyolefin resins obtained by modifying the same amounts of maleic anhydride and a radical generator (Examples 2 and 6). Compared with 3), the amount of unsaturated carboxylic acid modification is increased, and the bond strength to EVOH is also good. Also in this case, compared to the modified polyolefin resin (Comparative Example 6) obtained by supplying the entire amount of the radical generator to the first raw material supply port, the fisheye is better and the adhesive strength to EVOH is also superior.

Claims (8)

An extruder having two or more raw material supply ports in which (A) a polyolefin resin, (B) an unsaturated carboxylic acid and / or derivative thereof, and (C) a radical generator are arranged at different positions in the extrusion direction. And (C) in the presence of a radical generator, (A) a method for producing a modified polyolefin resin by graft-reacting (B) an unsaturated carboxylic acid and / or its derivative to a polyolefin resin,
(A) a polyolefin resin, and (B) an unsaturated carboxylic acid and / or a derivative thereof are supplied from the first raw material supply port on the most upstream side of the extruder,
(C) A method for producing a modified polyolefin resin, wherein a radical generator is supplied from two or more raw material supply ports.   2. The method for producing a modified polyolefin resin according to claim 1, wherein (C) the radical generator is supplied from at least the first raw material supply port and the second second raw material supply port from the upstream side of the extruder.   2. The production of a modified polyolefin resin according to claim 1, wherein (C) the radical generator is supplied at least from the second second raw material supply port and the third third raw material supply port from the upstream side of the extruder. Method.   4. When supplying the radical generator (C) from n (n ≧ 2) raw material supply ports according to claim 1, the most upstream raw material among the n raw material supply ports. A method for producing a modified polyolefin resin, characterized in that the supply amount of the radical generator supplied from the supply port is less than 1 / (n-1) of the total supply amount of the (C) radical generator to the extruder. .   5. The extruder according to claim 1, wherein the extruder is a twin-screw extruder having at least the same number of reaction kneading units as the raw material supply ports on the downstream side of the raw material supply ports. (A) Addition of unsaturated carboxylic acid and / or derivative thereof to (A) polyolefin resin by melt-kneading the polyolefin resin at a temperature of 180 to 270 ° C., and (A) retention of polyolefin resin in the extruder A process for producing a modified polyolefin resin, characterized in that the melt extrusion is carried out with the time being at least three times the 99.9% decomposition time of the (C) radical generator at the resin temperature.   The raw material supply port according to any one of claims 1 to 5, wherein the (C) radical generating agent is supplied, and the second raw material supply port after the second second raw material supply port from the upstream side of the extruder. (D) Carbon dioxide gas and / or nitrogen gas is supplied from (D) Unsaturated carboxylic acid and / or its derivative is added to (A) polyolefin resin in the presence of carbon dioxide gas and / or nitrogen gas. And then, carbon dioxide gas and / or nitrogen gas is separated from the vent port.   A modified polyolefin resin produced by the method for producing a modified polyolefin resin according to any one of claims 1 to 6.   An adhesive modified polyolefin resin composition comprising the modified polyolefin resin according to claim 7 and an unmodified polyolefin resin, wherein a weight ratio of the modified polyolefin resin to the unmodified polyolefin resin is 1:99 to 99. : Adhesive modified polyolefin resin composition characterized by being in the range of: 1.