JPH11106578A - Olefin resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermally reversibly crosslinkable olefin resin compsn. by compounding a modified olefin resin having on average at least two carboxylic anhydride groups with a hydroxyl compd. having no prim-OH group and having at least two sec-OH groups in a specified ratio. SOLUTION: This compsn. is prepd. so that the ratio of the number of carboxylic anhydride groups to that of hydroxyl groups is 0.1-10. Examples of the hydroxyl compd. are represented by formula I (wherein R<1> and R<2> are each 1-20C linear or cyclic alkylene; a and b are each an integer of 0 or higher; and c is an integer of 1 or higher) and formula II (wherein R<3> and R<6> are each 1-20C linear or cyclic alkyl, alkoxy, an arom. group, R<4> and R<5> are each 1-20C linear or cyclic alkyl alkoxy, an aromatic group or oxy; d and e are each an integer of 0 or higher; and f is an integer of 1 or higher). The compsn. has high crosslink-forming and crosslink-dissociating properties, an excellent thermally reversible crosslinkability, and excellent heat resistance and melt flowability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an olefin resin composition, and more particularly, to a so-called thermoreversible crosslinkable olefin resin capable of repeatedly forming a crosslink at a low temperature and dissociating the crosslink at a high temperature. Composition.

[0002]

2. Description of the Related Art Olefinic resins such as polyethylene and polypropylene are excellent in moldability, mechanical strength, transparency, chemical resistance, etc., and are variously molded such as extrusion molding, injection molding, hollow molding, compression molding, and rotational molding. It is widely used in various fields by being shaped into a desired shape in the molten state by the method. Also, in order to impart heat resistance and improve mechanical strength at high temperatures, etc., compounding of organic peroxide, irradiation of radiation Alternatively, it is also widely used as a crosslinked body which has been subjected to a crosslinking treatment by utilizing a silanol condensation reaction or the like. On the other hand, from the standpoint of environmental protection and resource saving,
It is becoming increasingly necessary to reuse used resins.However, this crosslinked resin is used as a crosslinked resin.
It is no longer thermoplastic and cannot be reused by melt molding, and there is a strong demand for compatibility between this crosslinked product and thermoplasticity.

On the other hand, at low temperatures, crosslinks are formed,
In contrast to some conventional techniques as a method of dissociating the crosslinks at high temperature to impart thermoplasticity, an olefin resin composition having excellent thermoreversible crosslinkability, particularly high crosslink formation reaction rate and crosslink dissociation reaction rate JP-A-6-5
Nos. 7062 and 7-94029,
Unsaturated carboxylic anhydride-modified olefin-based resin and a polyhydric alcohol compound having at least two hydroxyl groups in a molecule, for example, glycols such as ethylene glycol,
Alcohols such as 1,4-butanediol, sugars such as sorbitol, polyoxyalkylene compounds such as trimethylolpropane, polyglycerin alkyl esters such as diglycerin monostearate, sorbitan alkyl esters such as sorbitan monostearate An olefin resin composition comprising a polymer having a plurality of hydroxyl groups in a molecule such as a polyolefin oligomer having a plurality of hydroxyl groups and a reaction accelerator such as a metal salt of an organic carboxylic acid is disclosed.

According to studies by the present inventors, a thermoreversible crosslinkable composition based on the reaction between a carboxylic acid anhydride group and a hydroxyl group basically comprises one molecule of a carboxylic acid anhydride group. And one molecule of hydroxyl group reacts to form a carboxylic acid monoester, and one reaction of the generated carboxylic acid monoester and one molecule of hydroxyl group further reacts to form a carboxylic acid diester. The former carboxylate monoester formation reaction has good thermoreversibility, but the latter carboxylate diester formation reaction has poor thermoreversibility. The metal salt formation reaction between the group and the organic carboxylic acid metal salt also occurs at the same time, and the cross-linking reaction rate is excellent, but this metal salt formation reaction is easily dissociated at high temperatures, Since the ester formation reaction is reduced by the occurrence of this reaction, the degree of heat-resistant cross-linking as a whole is reduced, and as a result, the heat resistance of the composition is inferior, and the formation of the carboxylic acid diester described above. However, it has been found that there is a problem that the melt fluidity is reduced when the heat resistance is increased.

[0005]

SUMMARY OF THE INVENTION Based on the results of the above-mentioned studies on the prior art, the present inventors have developed a thermoreversible cross-linking method which is excellent in a cross-linking reaction rate and a cross-linking dissociation reaction rate without using a metal salt of an organic carboxylic acid. As a result of intensive studies to obtain a functional olefin resin composition, the present invention has been achieved,
Therefore, an object of the present invention is to provide an olefin-based resin composition having high thermoreversible crosslinkability having high crosslinkability and crosslink dissociation, and excellent heat resistance and melt fluidity.

[0006]

Means for Solving the Problems The present inventors have found that the above objects can be achieved by blending a specific hydroxyl group-containing compound with an unsaturated carboxylic anhydride-modified olefin resin, and have completed the present invention. In other words, the present invention relates to the following (A) and (B) components: (A) a carboxylic acid anhydride-modified olefin resin having an average number of carboxylic anhydride groups of 2 or more per molecule. (B) having no hydroxyl group bonded to a primary carbon atom,
An olefin resin composition comprising a hydroxyl group-containing compound having two or more hydroxyl groups bonded to a secondary carbon atom, wherein the ratio of the number of hydroxyl groups of the component (B) to the number of carboxylic anhydride groups of the component (A) is 0.1 to 10. Make the object a summary.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The carboxylic anhydride-modified olefin resin as the component (A) in the present invention basically includes a copolymer of an α-olefin and an ethylenically unsaturated carboxylic anhydride, There is a graft of an α-olefin resin with an ethylenically unsaturated carboxylic anhydride.

The α-olefin in the former copolymer includes, for example, ethylene, propylene, butene-1,
4-methylpentene-1, hexene-1 and the like. Examples of the ethylenically unsaturated carboxylic acid anhydride include 2-octen-1-yl succinate anhydride,
2-dodecene-1-yl succinate anhydride, 2-succinic acid 2-
Octadecene-1-yl anhydride, maleic anhydride,
2,3-dimethylmaleic anhydride, bromomaleic anhydride, dichloromaleic anhydride, citraconic anhydride, itaconic anhydride, 1-butene-3,4-dicarboxylic anhydride, 1-cyclopentene-1 , 2-dicarboxylic anhydride, 1,2,3,6-tetrahydrophthalic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, ex
o-3,6-epoxy-1,2,3,6-tetrahydrophthalic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, methyl-5-norbornene-2,3-dicarboxylic anhydride, endo-bicyclo [2.2.2] oct-5-ene-2,3-dicarboxylic anhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic acid Anhydrides and the like.

The former copolymer includes, in addition to the above-mentioned binary copolymer of α-olefin and the above-mentioned ethylenically unsaturated carboxylic anhydride, an ethylenically unsaturated copolymer such as acrylic acid, methacrylic acid and maleic acid. Saturated carboxylic acid compounds, vinyl acetate, methyl acrylate, ethylenically unsaturated ester compounds such as methyl methacrylate, acrylamide, methacrylamide, ethylenically unsaturated amide compounds such as N-methylacrylamide, styrene, acrylonitrile,
It may be a ternary or higher multi-component copolymer obtained by copolymerizing other ethylenically unsaturated compounds such as methacrylonitrile. Among these copolymers, a binary or multi-component copolymer of ethylene and an ethylenically unsaturated carboxylic anhydride, particularly maleic anhydride, is preferred, and these copolymers are conventionally known, It can be produced by a polymerization method such as lump, solution, suspension and the like.

The α-olefin resin in the latter graft is, for example, a homopolymer of ethylene (branched or linear) such as low-density / medium-density / high-density polyethylene, ethylene and propylene, Butene-1, 3-
Copolymers with α-olefins such as methylbutene-1, pentene-1, 3-methylpentene-1, 4-methylpentene-1, hexene-1, octene-1, and decene-1;
Ethylene resins such as ethylene and vinyl esters such as vinyl acetate, copolymers of acrylic acid, methacrylic acid, or other monomers such as esters thereof, homopolymers of propylene, propylene, ethylene, butene- 1,3-methylbutene-1, pentene-1,3-methylpentene-
Copolymers with α-olefins such as 1,4-methylpentene-1, hexene-1, octene-1, decene-1, propylene, isoprene, 1,3-butadiene, 1,3
Propylene resins such as copolymers with other monomers such as diene compounds such as pentadiene, 1,4-hexadiene, 1,5-hexadiene and 1,9-decadiene, and butene-1,4-methylpentene; -1, hexene-1 etc. α
-Olefin homopolymers and copolymers.

Further, as the ethylenically unsaturated carboxylic anhydride, the same ones as mentioned in the copolymer can be used. Among these grafts, those obtained by grafting an ethylenically unsaturated carboxylic acid anhydride, particularly maleic anhydride, to an ethylene-based resin or a propylene-based resin are preferable.
It can be produced by a grafting method such as melt kneading, solution, suspension and the like.

In the present invention, the content of the ethylenically unsaturated carboxylic acid anhydride unit as the carboxylic acid anhydride-modified olefin resin of the component (A) is 0.1% by weight.
As described above, the content is particularly preferably 1.0% by weight or more, and as a carboxylic acid anhydride group per one molecule of the modified olefin resin, which is obtained from a multiplier of the number average molecular weight of the modified olefin resin and the content thereof. It is essential that the average number of bonds is two or more. Here, the average number of bonds is 2
If it is less than the number, the degree of crosslinking of the composition becomes insufficient, and the object of the present invention cannot be achieved in terms of heat resistance.
As the carboxylic acid anhydride-modified olefin resin of the component (A) in the present invention, a modified olefin resin may be an unmodified olefin resin as long as the average number of bonds per carboxylic acid anhydride group per molecule is satisfied. It may be diluted with a resin.

In the present invention, the hydroxyl group-containing compound of the component (B) which forms a cross-link by binding to the carboxylic acid anhydride group of the carboxylic acid anhydride-modified olefin resin of the component (A) is preferably a primary carbon atom. It is essential that the compound has no hydroxyl group bonded to a secondary carbon atom and has two or more hydroxyl groups bonded to a secondary carbon atom. Here, when the number of hydroxyl groups bonded to the secondary carbon atom is less than 2, the degree of crosslinking of the composition becomes insufficient, and the object of the present invention cannot be achieved in terms of heat resistance. Even if the number of hydroxyl groups bonded to the primary carbon atom is two or more, when the compound has a hydroxyl group bonded to the primary carbon atom, the dissociation of crosslinks as a composition becomes insufficient, and the object of the present invention in melt fluidity is as follows. Can not achieve.

Specific examples of the hydroxyl group-containing compound as the component (B) in the present invention include compounds represented by the following general formula (I).

[0015]

Embedded image

(Wherein R ¹ and R ² each independently represent a linear or cyclic alkylene group having 1 to 20 carbon atoms, a and b are integers of 0 or more, and c is an integer of 1 or more. Represents.)

As the compound represented by the general formula (I), specifically, for example, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 1,2-cyclopentanediol, 1,3-cyclopentanediol,
1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,
4-cyclooctanediol, 1,5-cyclooctanediol, 1,3,5-cyclohexanetriol, inositol and the like, among which 1,2-cyclopentanediol, 1,3-cyclopentanediol, 2
-Cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclooctanediol, 1,5-cyclooctanediol, and 1,3,5-cyclohexanetriol are preferred.

The hydroxyl group-containing compound as the component (B) also includes a compound represented by the following general formula (II).

[0019]

Embedded image

[0020] (wherein, R ³ and R ⁶ are each independently, represent a chain or cyclic alkyl group having 1 to 20 carbon atoms, an alkoxy group, or an aromatic group,, R ⁴ and R
⁵ each independently represents a linear or cyclic alkylene group having 1 to 20 carbon atoms, a carbonyl group, an aromatic group, or an oxy group, d and e are integers of 0 or more, and f is an integer of 1 or more. Represents )

As the compound represented by the general formula (II), specifically, for example, 2,3-butanediol,
2,4-pentanediol, 2,5-hexanediol, 1,1,1,5,5,5-hexafluoro-2,
2,4,4-pentane tetrol and the like, among which
2,3-butanediol, 2,4-pentanediol,
2,5-hexanediol is preferred.

Further, examples of the hydroxyl group-containing compound as the component (B) include a compound represented by the following general formula (III).

[0023]

Embedded image

[0024] (wherein, R ⁷ and R ⁹ each independently represent a cyclic alkylene group having 5 to 20 carbon atoms, R ⁸
Represents a linear or cyclic alkylene group having 1 to 20 carbon atoms, a carbonyl group, an aromatic group, or an oxy group, and g and h represent an integer of 1 or more. )

Specific examples of the compound represented by the general formula (III) include, for example, 4,4'-isopropylidene-dicyclohexanol, α, α'-bis (4-hydroxycyclohexyl) -1 , 4-diisopropylbenzene, α, α'-bis (4-hydroxycyclohexyl) -1,4-diisopropylcyclohexane, 4,
4'-methylenebis (cyclohexanol), 2,2 '
-Methylenebis (4-methylcyclohexanol) and the like, among which 4,4'-isopropylidene-dicyclohexanol, α, α'-bis (4-hydroxycyclohexyl) -1,4-diisopropylbenzene, α ,
α'-bis (4-hydroxycyclohexyl) -1,4
-Diisopropylcyclohexane is preferred.

In the olefin resin composition of the present invention, the composition ratio of the carboxylic acid anhydride-modified olefin resin of the component (A) to the hydroxyl group-containing compound of the component (B) is as follows. It is necessary that the ratio of the number of hydroxyl groups of the component (B) to the number of anhydride groups be 0.1 to 10, preferably 0.2 to 5. Here, when the ratio of the number of hydroxyl groups to the number of carboxylic anhydride groups is less than 0.1, the degree of crosslinking as a composition becomes insufficient, and the composition does not become satisfactory in heat resistance. The dissociation becomes insufficient and the melt fluidity becomes unsatisfactory, and in any case, the object of the present invention cannot be achieved.

The olefin resin composition of the present invention basically comprises the above-mentioned components (A) and (B), but the components (A) and (B) are not impaired in the effects of the present invention. Other components may be contained, specifically, for example,
Various additives commonly used, for example, antioxidants, ultraviolet absorbers, nucleating agents, neutralizing agents, lubricants, antiblocking agents, dispersants, flow improvers, release agents, flame retardants, colorants,
Fillers and the like can be added.

The olefin-based resin composition of the present invention comprises the above-mentioned components (A) and (B) as essential components, and other optional components. The components are mixed with a Henschel mixer, ribbon blender, V-type blender or the like. After mixing evenly,
Single or multi-screw extruders, rolls, Banbury mixers,
It can be prepared by melt-kneading with a kneader, Brabender or the like.

The olefin resin composition of the present invention as described above can be obtained in a molten state by various molding methods usually used for thermoplastic resins, that is, injection molding, extrusion molding, hollow molding, compression molding, rotational molding and the like. It can be shaped into a desired shape to form a cross-linked molded article. Also, when reusing a used molded article, etc., it can be re-shaped into a desired shape in a molten state by the same molding method and cross-linked. Can be a body.

[0030]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention.

Example 1 As the carboxylic acid anhydride-modified olefin resin as the component (A), a maleic anhydride graft-modified polypropylene resin (containing 9.5% by weight of maleic anhydride units as measured by infrared absorption spectrum, Number average molecular weight 400 measured by gel permeation chromatography
0, the average number of carboxylic acid anhydride groups per molecule of the modified polypropylene resin obtained from the multiplier of the number average molecular weight and the content of maleic anhydride units is 3.9, "UMEX 1010" manufactured by Sanyo Chemical Industries, Ltd.) 94 0.6% by weight,
As a hydroxyl group-containing compound of the component (B), 5.4% by weight of 2,5-hexanediol was used (the ratio of the number of hydroxyl groups to the number of carboxylic anhydride groups was 1), and Brabender Plastmill (manufactured by Toyo Seiki Co., Ltd.) was used. 5 at 230 ° C and 50 rpm
The mixture was melt-kneaded for 1 minute to prepare an olefin-based resin composition.
For the obtained composition, the melt index and the heat deformation ratio were measured by the following methods, and the appearance of the strand at the time of the melt index measurement was evaluated.
It was shown to.

The melt index measurement temperatures were 200 ° C., 230 ° C., 260 ° C., and 29 ° C.
The temperature was measured in accordance with JIS K7210 (method B) except for the case where the temperature was 0 ° C. Viewing the melt index strand appearance at the time of measurement of the observation in the strand appearance 290 ° C., × those strands ○ having no unevenness on is surface a substantially straight, remarkable surface roughness is observed with the strands themselves meanders Was evaluated. Heat deformation rate According to JIS C3005 (heat deformation), a test piece pressed at 200 ° C. was measured at 200 ° C. and 1 kgf.

Example 2 As the carboxylic acid anhydride-modified olefin resin of the component (A), a maleic anhydride graft-modified polypropylene resin (containing 2.4% by weight of maleic anhydride units as measured by infrared absorption spectrum, Number average molecular weight 140 measured by gel permeation chromatography
00, average number of carboxylic acid anhydride groups per molecule of modified polypropylene resin calculated from the number average molecular weight and the content of maleic anhydride units: 3.4) 98.7% by weight, and component (B) As a hydroxyl group-containing compound of 1,3,
An olefin resin composition was prepared in the same manner as in Example 1 except that 1.3% by weight of 5-cyclohexanetriol was used (the ratio of the number of hydroxyl groups to the number of carboxylic anhydride groups was 1), and the resulting composition was obtained. , The melt index and the heat deformation ratio were measured, and the appearance of the strand at the time of the melt index measurement was evaluated. The results are shown in Table 1.

Example 3 The component (A) was 94.9% by weight and the component (B) was 5.1.
An olefin-based resin composition was prepared in the same manner as in Example 2 except that the ratio was 4% by weight (the ratio of the number of hydroxyl groups to the number of carboxylic anhydride groups was 4), and the melt index and the heat deformation ratio of the obtained composition were measured. The strand was measured and the appearance of the strand at the time of melt index measurement was evaluated. The results are shown in Table 1.

COMPARATIVE EXAMPLE 1 The component (A) was 40% by weight, and the component (B) was 1,3-, having a hydroxyl group bonded to a terminal primary carbon atom.
Hydrogenated polymer of butadiene (having a hydroxyl content of 1.
0% by weight, number average molecular weight 5400, iodination 1.0 g / 1
(G) The average number of hydroxyl groups per polymer obtained from the multiplier of the number average molecular weight and the hydroxyl group content was 3.2, and 60% by weight was used (the ratio of the number of hydroxyl groups to the number of carboxylic anhydride groups is 1). An olefin-based resin composition was prepared in the same manner as in Example 1, and the resulting composition was measured for a melt index and a heat deformation rate, and the appearance of the strand at the time of the melt index measurement was evaluated. 1 is shown.

Comparative Example 2 An olefin was prepared in the same manner as in Comparative Example 1 except that 2 parts by weight of calcium stearate was added to 100 parts by weight of the total amount of the resin composition (the ratio of the number of hydroxyl groups to the number of carboxylic anhydride groups was 1). A resin composition was prepared, and the resulting composition was measured for a melt index and a heat deformation ratio.
Further, the appearance of the strand at the time of measuring the melt index was evaluated, and the results are shown in Table 1.

Comparative Example 3 An olefin was prepared in the same manner as in Comparative Example 1, except that 5 parts by weight of calcium stearate was added to 100 parts by weight of the total amount of the resin composition (the ratio of the number of hydroxyl groups to the number of carboxylic anhydride groups was 1). A resin composition was prepared, and the resulting composition was measured for a melt index and a heat deformation ratio.
Further, the appearance of the strand at the time of measuring the melt index was evaluated, and the results are shown in Table 1.

Comparative Example 4 The component (A) was 93.4% by weight, and the component (B) was
6.6 was added to 2,5-dimethyl-2,5-hexanediol.
An olefin resin composition was prepared in the same manner as in Example 1 except that the weight% used (the ratio of the number of hydroxyl groups to the number of carboxylic anhydride groups was 1), and the melt index and the heat deformation ratio of the obtained composition were measured. The strand was measured and the appearance of the strand at the time of melt index measurement was evaluated. The results are shown in Table 1.

Comparative Example 5 The component (A) was 95.8% by weight, and the component (B) was
An olefin-based resin composition was prepared in the same manner as in Example 1 except that 4.2% by weight of 1,4-butanediol was used (the ratio of the number of hydroxyl groups to the number of carboxylic anhydride groups was 1), and the resulting composition was obtained. The melt index and the heat deformation ratio of the product were measured, and the appearance of the strand at the time of the melt index measurement was evaluated. The results are shown in Table 1.

Reference Example 1 For the homopolypropylene resin, the melt index and the heat deformation were measured in the same manner as in Example 1, and the appearance of the strand at the time of measuring the melt index was evaluated. The results are shown in Table 1. .

[0041]

[Table 1]

[0042]

According to the present invention, there can be provided an olefin-based resin composition having high thermo-reversible cross-linking properties with high cross-linking and cross-linking dissociation properties and excellent heat resistance and melt fluidity.
Therefore, the olefin-based resin composition of the present invention can be formed into a desired shape in a molten state by a molding method generally used for a thermoplastic resin to obtain a cross-linked molded product. Even at the time of use or the like, a crosslinked molded article can be formed again in a molten state into a desired shape by a similar molding method.

Claims (4)

[Claims] 1. The following components (A) and (B): (A) a carboxylic acid anhydride-modified olefin resin having an average number of carboxylic acid anhydride groups per molecule of 2 or more; (B) a primary resin No hydroxyl group attached to the carbon atom,
A hydroxyl group-containing compound having two or more hydroxyl groups bonded to a secondary carbon atom, wherein the ratio of the number of hydroxyl groups of the component (B) to the number of carboxylic anhydride groups of the component (A) is 0.1 to 10. Olefin resin composition. 2. The olefin resin composition according to claim 1, wherein the hydroxyl group-containing compound as the component (B) is a compound represented by the following general formula (I). Embedded image (Wherein, R ¹ and R ² each independently represent a chain or cyclic alkylene group having 1 to 20 carbon atoms, a and b each represent an integer of 0 or more, and c represents an integer of 1 or more. ) 3. The olefin resin composition according to claim 1, wherein the hydroxyl group-containing compound as the component (B) is a compound represented by the following general formula (II). Embedded image (Wherein, R ³ and R ⁶ are each independently a chain or cyclic alkyl group having 1 to 20 carbon atoms, an alkoxy group,
Or an aromatic group, and R ⁴ and R ⁵ each independently represent a linear or cyclic alkylene group having 1 to 20 carbon atoms, a carbonyl group, an aromatic group, or an oxy group;
d and e each represent an integer of 0 or more, and f represents an integer of 1 or more. ) 4. The olefin resin composition according to claim 1, wherein the hydroxyl group-containing compound as the component (B) is a compound represented by the following general formula (III). Embedded image (Wherein, R ⁷ and R ⁹ each independently represent a cyclic alkylene group having 5 to 20 carbon atoms, R ⁸ is C 1 -C
~ 20 chain or cyclic alkylene groups, carbonyl groups,
Represents an aromatic group or an oxy group, and g and h represent an integer of 1 or more. )