JPH01254752A - Thin-walled article of ethylene copolymer mixture - Google Patents

Abstract

PURPOSE:To provide the subject thin-walled article composed of a mixture produced by compounding two specific kinds of ethylene copolymers at specific ratios, having high strength even at a relatively high temperature and suitable as a coating material, wrapping material, etc., for electric wire. CONSTITUTION:The objective thin-walled article can be produced by compounding (A) 1-99wt.% (preferably 10-90wt.%) of a copolymer of ethylene and an unsaturated monocarboxylic acid, unsaturated dicarboxylic acid and, optionally, a vinyl ester compound, an alkyl (meth)acrylate compound or an alkoxyalkyl acrylate compound with (B) 99-1wt.% (preferably 90-10wt.%) of a copolymer of ethylene and a monomer having epoxy group and containing one or more double bonds and, optionally, a vinyl ester compound, etc., in such a manner as to give a molar ratio of (epoxy group in the component B) : [carboxyl (anhydride) group in the component A] of 1:0.2-5 and forming the mixture in the form of a thin-walled article having a thickness of 10mum-5mm and a boiling xylene extraction residue of >=25wt.% and <95wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a thin-walled product of an ethylene copolymer mixture having at least 2 F weight and excellent heat resistance. More specifically, the present invention relates to a thin product made of an ethylene copolymer mixture that has a strength comparable to that of general low-density polyethylene at room temperature and has heat-resistant strength at relatively high temperatures.

[Conventional technology]

Current (1: ethylene polymer containing ethylene as the main component,
Propylene-based polymers containing propylene as the main component are inexpensive, have good moldability, and have excellent cross-sectional properties (especially flexibility), so they are used in extrusion molding methods, blow molding methods, etc. It is made into films, sheets, various containers, etc., and is used in many ways.

[Problem to be solved by the invention]

However, ethylene homopolymers and ethylene-based copolymers mainly composed of ethylene, such as high-density polyethylene (HDPE), low-density polyethylene (LDPE), and ethylene-vinyl acetate copolymer (EVA), have poor heat resistance. This is not satisfactory in this respect. On the other hand, although propylene homopolymers and propylene copolymers containing propylene as the main component have better heat resistance than the ethylene 111 homopolymers and ethylene copolymers, they are not necessarily satisfactory. I can't say that.

Furthermore, the strength at relatively high temperatures is not entirely satisfactory.

From the above, the present invention does not have these drawbacks (problems), and in other words, it improves the heat resistance, which was the drawback of the ethylene copolymers and propylene copolymers, and also improves the heat resistance strength at relatively high temperatures. The objective is to obtain a thin material that is H.

[Means and effects for solving the problems] According to the present invention, these problems are solved by: (A) Combination of ethylene and unsaturated monocarboxylic acid, unsaturated monocarboxylic acid or its anhydride, or these and “vinyl ester compound”. , an alkyl (meth)acrylate compound or an alkoxyalkyl acrylate compound” (hereinafter referred to as “third comonomer”)! Ii
(1), (B) A thin mixture of ethylene and a monomer having an epoxy group and at least one double bond, or a copolymer (II) of these and a third comonomer. The mixing ratio of copolymer (I) in the total amount of copolymer (1) and copolymer (II) is 1 to 99% by weight, or the copolymer (II)
The total molar ratio of carboxyl groups and anhydride groups in the ethylene copolymer (1) is 1:0.2 to 5.
．． 0, the thickness of the meat is between 10 mm and 5 mm, and the "extraction residue of boiling xylene" (
(hereinafter referred to as "extraction residue") is 25% by weight or more,
Thinning of the ethylene-based copolymer mixture is less than 95% by weight. The present invention will be explained in detail below.

(A) Copolymer (1) The ethylene copolymer (1) used in the present invention is broadly classified into the following ethylene copolymers.

(1) Copolymer of ethylene and unsaturated monocarboxylic acid or these and a third comonomer (hereinafter referred to as "copolymer (1)")
(2) Copolymers of ethylene and unsaturated dicarboxylic acids and/or their anhydrides, or copolymers of these and third comonomers (
The number of carbon atoms in the unsaturated monocarboxylic acid which is the monomer component of copolymer (1) (hereinafter referred to as "1-polymer (2)") is generally 3 to 20, particularly 3 to 10. Preferably. Representative examples of preferred unsaturated monocarboxylic acids include acrylic acid, methacrylic acid, crotonic acid, monoalkyl fumarate, and monoalkyl maleate.

Further, the number of carbon atoms in the unsaturated dicarboxylic acid and its anhydride which are the monomer components of the copolymer (2) is usually 4 to 20, and 4 to te (hard ones are preferable, especially 4 to 1
Two are preferred. Representative examples of suitable unsaturated dicarboxylic acids and their anhydrides include maleic acid, fumaric acid, itaconic acid, citraconic acid and 3,6-nindomethylene-1,2,3,6-tetrahydro-cis-phthalic acid (nadic acid). [F]) and anhydrides of these unsaturated dicarboxylic acids.

The vinyl ester compound which is the third comonomer of these copolymers (1) and copolymers (2) generally has at most 20 carbon atoms (preferably 4 to 1 G fl,
M, preferably 4 to 10). Suitable vinyl ester compounds include vinyl acetate, vinyl propionate, vinyl butyrate and vinyl pivalate.

The alkyl (meth)acrylate compound usually has at least 20 carbon atoms, preferably 4 to 16 carbon atoms, and particularly preferably 4 to 10 carbon atoms. Representative examples of suitable alkyl (meth)acrylate compounds include methyl acrylate, methyl methacrylate, ethyl acrylate and ethyl methacrylate.

Furthermore, the alkoxyalkyl acrylate usually has at most 20 carbon atoms. Furthermore, the alkyl group preferably has 1 to 8 carbon atoms (preferably 1 to 4 carbon atoms), and the alkoxy group preferably has 1 to 8 carbon atoms (preferably 1 to 4 carbon atoms).
4 pieces) is preferable. Representative examples of preferred alkoxyalkyl acrylates include methyne ethyl acrylate, ethyne ethyl acrylate-1- and butkiethyl acrylate.

In the case of the above-mentioned copolymer (1) and copolymer (2), the copolymerization ratio of the second comonomer is generally 20 mol% or less as a total amount, especially 15 mol%. % or less is suitable. Even if more than 20 mol % of copolymer (1) is used, the characteristics of the present invention are exhibited, but it is economically problematic to produce an ethylene copolymer in this range.

Further, in the copolymer (1), the copolymerization ratio of unsaturated monocarboxylic acid is generally 0.1 to 15 mol%, and 0.
．． 2 to 15 mol%, preferably 0.5 to 15 mol%
is suitable. Further, in the copolymer (2), the copolymerization ratio of unsaturated dicarboxylic acid and its anhydride is usually 0.1-15 mol% in total, preferably 0.2-15 mol%, especially 5 to 15 mol% is suitable. If the copolymerization ratio of the unsaturated monocarboxylic acid or unsaturated dicarboxylic acid and its anhydride in the copolymer (2) is less than the lower limit, the heat resistance of the thin product obtained is poor.

On the other hand, if the upper limit is exceeded, it is economically problematic to produce such copolymers.

(13) Copolymer (II) Also, "a monomer having an epoxy group and having at least one double bond" (hereinafter referred to as "epoxy Typical examples of the "compounds" are those whose general formulas are represented by the following formulas (Formula (I) and Formula (II)).

(Remaining 11 below) In formula (1) and formula (n), R,, R2.

R and R4 are preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, particularly preferably an alkyl group having 1 to 4 carbon atoms.

Representative examples of suitable epoxy compounds represented by formulas (1) and (II) above include glycidyl methacrylate, glycidyl acrylate-1, a-methylgrindyl acrylate, α-methylglycidyl methacrylate, vinyl Mention may be made of glycidyl ether, allyl glycidyl ether and methallyl glycidyl ether.

The copolymer (II) of the present invention may be a copolymer of the ethylene and the epoxy compound, or a multicomponent copolymer of ethylene, the epoxy compound, and the third comonomer.

In this copolymer, the copolymerization ratio of the epoxy compound is generally 0.1 to 15 mol%, and 0.1 to 1 O
A mole % is desirable, and a range of 0.2 to 10 mole % is particularly preferred. If the copolymerization ratio of the epoxy compound is less than the lower limit, crosslinking will be insufficient and a thin product with good heat resistance cannot be obtained. On the other hand, if the copolymer content exceeds 15 mol %, it is not preferable from the viewpoint of manufacturing and economical aspects of the copolymer.

The copolymerization ratio of the third comonomer is the same as that of the above-mentioned copolymer (2).
For the same reason as in the above case, those within the above copolymerization range are preferred.

These copolymers (1) and copolymers (II) are
0 ~ 2500kg/ct ultra high pressure, 120 ~ 2
They are produced industrially by radical polymerization using free radical generators (mainly organic peroxides) at a temperature of 00°C, and are used in a wide range of fields, and their manufacturing methods are well known. It is being

Melt flow index of these ethylene copolymers (based on JIS K-7210, conditions are 4 and Jll
The above (referred to as MFRJ) are usually 0.0.
1~loog/10 minutes and 0.05~50g/10
0.1 to 50/10 minutes is particularly preferred.

In producing the mixture of the present invention, the copolymer (I) is a copolymer of ethylene and an α,β-unsaturated monocarboxylic acid or an α,β-unsaturated dicarboxylic acid, or a copolymer of these and a third comonomer. When using a multi-component copolymer,
The thin-walled article of the present invention can be produced by heating the copolymer (II) as described below. but,
When using a copolymer of ethylene and anhydride of α,β-unsaturated dicarboxylic acid or a multi-component copolymer of these and a third comonomer, crosslinking may be incomplete if the copolymer (TI) and heating are used alone. be. From this, "It is an organic compound or polymer whose boiling point is 150°C or higher, and hydroxyl u (-0Hg) and carboxyl group (-COOHJ
Crosslinking can be achieved by using a compound that binds to the organic compound (hereinafter referred to as an "organic compound, etc.").

(C) Organic compounds Representative examples of organic compounds having the above characteristics include saponified copolymers of ethylene and vinyl acetate,
Copolymers of ethylene and hydroxyalkyl (meth)acrylates as well as polymers mainly composed of ethylene or propylene (including Chinese-German polymers) containing ethylene and a monocarboxylic acid or half ester having at most 20 carbon atoms. Examples include copolymers with white monomers, and modified olefin polymers obtained by graft polymerization of α, β-unsaturated monocarboxylic acids, α, β-unsaturated dicarboxylic acids, or their anhydrides. Furthermore, examples of organic compounds include ethylene glycol, polyethylene glycol, propylene glycol, glycerin, and polypropylene glycol.

(D) Mixing ratio In the mixture of the present invention, the mixing ratio of any one of the ethylene copolymers in the total amount of the ethylene copolymer (A) and the ethylene copolymer (B) is 1 to 99% by weight. %
[That is, the mixing ratio of the ethylene copolymer (A) is 1
~99 weight? δ, the mixing ratio of the ethylene copolymer (B) is 99 to 1% (ML9'O), preferably 5 to 95%, and particularly preferably 10 to 90%.

Is the mixing ratio of any of these ethylene copolymers in the total amount of ethylene copolymers equal to 1 weight? If it is less than 6, the crosslinking properties of the mixture will be insufficient, and the resulting thin products will have poor heat resistance.

Further, when an organic compound or the like is mixed, the amount is generally at most 10 parts by weight, preferably 5 parts by weight or less, based on 100 parts by weight of the total amount of these ethylene copolymers.

Ethylene-based! Even if more than 10 parts by weight is mixed with respect to 100 parts by weight of the total amount of fi combined, the crosslinking property cannot be further improved, which is rather unfavorable in terms of the physical properties of the thin product obtained.

In addition, the ratio of the total amount of the carboxylic acid group and its anhydride group of the ethylene copolymer (A) to the epoxy group of the ethylene copolymer in the mixture is 0.2 to 5.0 in molar ratio, 0.3 to 3.0 is desirable, especially 0.5 to 2
．． 0 is preferred. Even if the molar ratio of the total amount of carboxylic acid groups and their anhydride groups to epoxy groups is less than 0.2 or more than 5.0, it is impossible to obtain a thin-walled product with good heat resistance. .

Furthermore, when producing the mixture of the present invention, when blending the above-mentioned hydroxyl group or carboxyl organic compound and/or polymer, the mixing ratio thereof is the sum of the above-mentioned copolymer (I) and copolymer (n). = usually at most 20 parts by weight to loo parts by weight, and from 0.1 to
20 parts by weight are desirable, 0.5 to 2.0 parts by weight are preferred, and especially 1.0 to 15 parts by weight are preferred.

(E) Mixing method In order to produce the liH compound of the present invention, these copolymers (T) and copolymers (II) or these ethylene copolymers and the above-mentioned compound a are uniformly mixed. Just let it happen. At this time, additives such as light, oxygen and heat stabilizers, lubricants, plasticizers, antistatic agents, flame retardants, fillers, and tube coloring agents, which are commonly used in the field of olefin polymers, are added. (blending).

The mixing method may be tri-blending using a mixer such as a Henschel mixer, which is commonly used in the field of olefin polymers, or melt-kneading using a mixer such as a Banbury, extruder, or roll mill. can give. At this time, a more uniform mixture can be obtained by triblending in advance and melt-kneading the resulting mixture. When melt-kneading, it is necessary that the mixed components do not substantially undergo cross-linking or N-reaction (if cross-linking occurs, not only will the moldability deteriorate when the resulting mixture is molded as described below), but it will also be difficult to meet the intended purpose. (This is undesirable because it causes a decrease in the shape of the molded product and the heat resistance when crosslinking the molded product.) From this, the melt-kneading temperature depends on the types and amounts of copolymer (1) and copolymer (II) used, as well as whether or not the reaction accelerator is added;
20°C) to 150°C, preferably 140°C or higher.

This "substantially non-crosslinked" (as a guideline, the extraction residue should generally be 15% by weight or less based on the total amount of copolymer (I) and copolymer (II) in the mixture. is preferable, preferably 10% to 6% by weight, and 5% by weight.
The following is optimal.

(F) Molding method The mixture thus obtained or the mixture containing additives can be molded into a film or sheet by the T-die method or circular die method, which is commonly used in the field of olefin polymers. Molded products having various shapes can also be manufactured by molding methods such as blow molding. Both the above-mentioned kneading and molding must be carried out at a temperature at which the polymer used melts. However, at high temperatures the polymer decomposes. For these reasons, the molding temperature is usually 110
-280°C, particularly preferably 120-250°C. Furthermore, various molded products can be produced at the above-mentioned molding temperature by a thermoforming method such as vacuum forming and single-pressure air forming, which is generally performed using a pre-obtained uncrosslinked sheet.

The thin-walled mixture of the present invention obtained as described above is
The extraction residue is at least 95! The If amount is 9°. On the other hand, if the extraction residue is less than 95 weight = 06, the heat resistance is poor.

The thickness of the thin material thus obtained is 10 μm to 5 m [l, preferably 10 tLn+ to 4 ml, particularly preferably 10 um to 3 mm. 10
If it is less than um, it is difficult to manufacture molded products.

During the above-mentioned molding, the extracted residue is preferably 15 times 6 or less for the above-mentioned reasons, and 10 weight? 6 or less is suitable;
Especially 5mm! ``6 or less is optimal.

However, for the above-mentioned reasons, the extraction residue of the finally obtained molded product (thin walled product) is 25% by weight or more, preferably 30% by weight or more, and particularly preferably 40% by weight or more. If the extraction residue of the thin material is less than 25% by weight, the heat resistance will be poor. However, if the extraction residue of the thin meat is 95% by weight or more, the heat resistance strength of the meat A'i is not good. Therefore, it is essential that the extraction residue is less than 95% by weight.

[Examples and comparative examples]

The present invention will now be explained in more detail with reference to Examples.

In addition, in the Examples and Comparative Examples, the heat resistance was measured by cutting the sample into 15 mm width and measuring the constant temperature. The deformation state of the sample was measured when it was left at a measurement temperature of 200°C for 2 minutes in a Tensilon type tensile tester equipped with FA tQ. In Table 1, the sample is shown as "O" if it is in its original shape, or "x" if it is deformed. In addition, the tensile strength at break was measured using a Tensilon type tensile tester with a constant temperature bath, at the measurement temperature shown in Table 1, with a chuck distance of 20 m + i, and a tensile speed of 500.
The intensity in mm/min (~ID direction) was measured. Furthermore, a sample of impact-strength melon with a thickness of 80 to 90 um and a diameter of 5.0 cm was held in a constant temperature bath maintained at a temperature of 200°C, and a 5.4 g iron ball was dropped from a height of 52 cm. The shape of the sample was observed. "○" indicates that the shape of the sample is maintained, and "○" indicates that the iron ball penetrates the sample, and the MFR is 270 g/10 min. The ethylene-acrylic acid copolymer has an acrylic acid copolymerization ratio of 25% by weight and an MFR of 7.0g/10 min, and a vinyl acetate copolymerization ratio of 5.0% by weight, and Ethylene-vinyl acetate-glycidyl methacrylate binary copolymer with a glycidyl methacrylate copolymerization ratio of 10% by weight, respectively, at a ratio of 20:80 (
(weight ratio) and 90:10 (weight ratio). Each mixture (hereinafter referred to as "mixture (
A) J, and "Mixture (B)"), MF
R is 210 g/10 min, and 1. ! An ethylene-maleic anhydride-ethyl acrylate ternary copolymer having a combined fL ratio of 2.8 mol%, a co-irL ratio of ethyl acrylate of 9.5 mol%, and a hydrolysis rate of 100%. Ethylene which has a combined mass of 40 parts and an MFR of 7.0 g/10 minutes, a copolymerization rate of vinyl acetate of 2.0 mol%, and a copolymerization ratio of glycidyl methacrylate of 23 mol%. 60 parts by weight of vinyl acetate-glycidyl methacrylate terpolymer (hereinafter referred to as "mixture (C
)" and 40 parts by mass of the ethylene-maleic anhydride-ethyl acrylate terpolymer used in producing the mixture (13) and an MFR of 130 g/lO.
minutes, and the copolymerization ratio of methyl methacrylate is 8
．． 2 mol 26, and the copolymerization ratio of allyl grindyl ether is 3.2 mol %, terpolymer 50!
fi parts (hereinafter referred to as "mixture (D)") were produced by triblending.

Using an inflation molding machine (cylinder diameter: 60 cm), each mixture obtained in this way was molded into a part of the cylinder.
1. The temperatures of C2 and C3, the head and the die were set to 95°C, 95°C, 110"C, 100"C and 100"C, respectively, and film forming was carried out. Both were about 100" thick and transparent. Moreover, a clean uncrosslinked thin material without gel or fish eyes was produced.

Each uncrosslinked film thus obtained was sandwiched between Teflon sheets and pressed at a temperature of 200°C for varying times to produce thin products whose extraction results are shown in Table 1. The heat resistance of each thin-walled product (all Jψ values are 95) obtained in this way.

The tensile strength at break was measured. The results obtained are shown in Table 1.

For comparison, high-pressure polyethylene (low-density polyethylene, hereinafter referred to as rLDPEJ) has an MFR of 0.8 g/min and a density of 0.920 g/c-.
The heat resistance and tensile strength at break of a film (thickness 10100I1) were measured. The obtained results are shown in Table 1.

〔Effect of the invention〕

The thin-walled ethylene copolymer mixture of the present invention exhibits the following effects.

(1) Generally used high-pressure polyethylene (low-density polyethylene) has the same strength at room temperature and has heat-resistant strength even at relatively high temperatures (for example, 200°C).

(2) It does not deform even at temperatures as high as 200°C.

The thin-walled ethylene copolymer mixture of the present invention can be used in a wide variety of ways to achieve the above-mentioned effects. Typical uses are shown below.

(1) Wire sheathing material

Claims (1)

[Scope of Claims] (A) Copolymerization of ethylene and unsaturated monocarboxylic acid, unsaturated dicarboxylic acid, or their anhydride, or these and vinyl ester compounds, alkyl (meth)acrylate compounds, or alkoxyalkyl acrylate compounds (I) and (B) a monomer having ethylene and an epoxy group and at least one double bond, or a combination of these with a vinyl ester compound, an alkyl (meth)acrylate compound, or an alkoxyalkyl acrylate compound. A thin mixture of copolymer (II) and
The mixing ratio of copolymer (I) in the total amount of copolymer (I) and copolymer (II) is 1 to 99% by weight, but the epoxy group in copolymer (II): Polymer (I
), the ratio of the total amount of carboxyl groups and its anhydride groups is 1:0.2 to 5.0 in molar ratio, the thickness of the thin material is 10 μm to 5 mm, and the boiling xylene in the thin material is The extraction residue is 25% by weight or more, but less than 95% by weight.