JPH0237942B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a thermoplastic elastomer composition sheet, and more particularly, to a method for producing a thermoplastic elastomer composition sheet by calendar-molding an olefin-based thermoplastic elastomer composition. be.

In order to improve the moldability of a thermoplastic elastomer made of a partially crosslinked product of ethylene/α-olefin copolymer rubber and a polypropylene resin, the applicant has proposed adding a mineral oil-based softener to the thermoplastic elastomer. (For example, Japanese Patent Application Laid-Open No. 149240
Publication No. 53-145857, etc.). Although the intended purpose was effectively achieved by incorporating such a mineral oil softener, it was discovered that there were some new problems.

In other words, although thermoplastic elastomers containing mineral oil softeners are suitable for injection molding, extrusion molding, etc. of thick-walled products, they cannot be used to produce sheet-like molded products using calendar molding. We have found the drawback that it is extremely difficult to do so due to its stickiness to the roll. This phenomenon is more likely to occur when the blending ratio of the softener increases, for example when the weight ratio of the mineral oil softener to the total amount of partially crosslinked rubber and polypropylene resin is about 5/100 or more, or when the proportion of crosslinked rubber increases. It was confirmed that the higher the ratio, specifically when the weight ratio of the partially crosslinked rubber to the polypropylene resin was about 150/100 or more, the more likely it was to occur. However, these weight ratio ranges are also preferred blending ratio ranges for thermoplastic elastomers, as described in each of the above-mentioned patent publications, so without essentially changing such blending ratios, It is strongly desired to solve the above problems.

As a result of various experiments and studies to solve these problems, the inventors of the present invention discovered that ethylene/α-olefin was combined with a mineral oil-based softener and a higher fatty acid amide before dynamic heat treatment for partial crosslinking. Knead into polymerized rubber and polypropylene resin,
It has been found that a composition with good calendar moldability can be obtained by adding and kneading a polyethylene resin to a thermoplastic elastomer obtained by dynamic heat treatment. The present invention was completed based on this knowledge.

The purpose of the present invention is to improve the disadvantage of the conventional olefin-based thermoplastic elastomer composition, which is composed of a partially crosslinked ethylene/α-olefin copolymer rubber, a polypropylene resin, and a mineral oil-based softener, and is unable to be calendered. An object of the present invention is to provide a method for producing a thermoplastic elastomer composition that allows calendar molding.

According to the present invention, 90 to 40 parts by weight of ethylene/α-olefin copolymer rubber (a), polypropylene resin
(b) 10 to 60 parts by weight of (a) + (b) in a total amount of 100 parts by weight, mineral oil softener (c) 5 to 100 parts by weight, and (a) + (b)
Thermoplastic elastomer 100 is added to the thermoplastic elastomer obtained by dynamically heat-treating a kneaded product of 0.05 to 3 parts by weight of higher fatty acid amide per 100 parts by weight of +(c) in the presence of an organic peroxide.
A method for producing a thermoplastic elastomer composition sheet is provided, which comprises adding and kneading 10 to 100 parts by weight of a polyethylene resin and calendering the composition.

Specifically, the ethylene/α-olefin copolymer rubber used in the present invention includes ethylene and 3 carbon atoms.
Molar ratio of ~14 α-olefins is approximately 50/50 to 90/
10, preferably about 55/45 to 85/15 binary copolymer rubber, or further copolymerized with various polyene compounds in an amount such that the iodine value is about 50 or less, preferably about 40 or less. It is a terpolymer rubber.

The blending ratio of ethylene/α-olefin copolymer rubber (a) and polypropylene resin (b) is 90/10 to 40/60.
Mix so that If there is more component (a) than 90/10, the purpose of adding component (b) cannot be achieved, and from 40/60 (b)
If there are too many components, the elastomer properties and calendar moldability of the thermoplastic elastomer will deteriorate.

The mineral oil softener is a petroleum fraction with a high boiling point, and may be paraffinic, naphthenic, aromatic, or a mixture thereof. Processing oils normally used for rubber can be used.

The mineral oil softener (c) is blended in an amount of 5 to 100 parts by weight based on 100 parts by weight of the sum of the ethylene/α-olefin copolymer rubber (a) and the polypropylene resin (b). If it is less than 5, the addition effect will not be exhibited,
If it exceeds 100, the heat resistance of the thermoplastic elastomer may decrease and the softener may ooze out, which is not preferable.

As higher fatty acid amides, amides of C ₈ to _{C 22} saturated straight chain fatty acids or monounsaturated fatty acids are preferably used, and specific examples include balmitic acid amide, stearic acid amide, behenic acid amide, oleic acid amide, and erucamide. Acid amides and the like are used. In addition, as higher fatty acid amides, N,N of C ₈ to C ₂₂ such as N,N'-methylenebiscaproic acid amide, N,N'-methylenebiscaprylic acid amide, N,N'-methylenebiscaprylic acid amide '-Methylene (or ethylene) bis higher fatty acid amides can also be used. These higher fatty acid amides are the total amount of ethylene/α-olefin copolymer rubber (a), polypropylene resin (b) and mineral oil softener (c) ((a) + (b) + (c)) 100 It is added in a proportion of 0.05 to 3 parts by weight, preferably about 0.1 to 1 part by weight. If the addition ratio is increased more than this, the physical properties of the thermoplastic elastomer will be deteriorated, and if it is less than this, the desired effect will not be obtained.

Addition and kneading of the mineral oil softener and higher fatty acid amide to the ethylene/α-olefin copolymer rubber and polypropylene resin can be carried out using various blenders, extruders, mixing rolls, kneaders, Banbury mixers, etc.

It is then granulated into pellets, which are dynamically heat treated in the presence of an organic peroxide. A conventionally known method is used for this dynamic heat treatment method.

Then, polyethylene resin is added and kneaded to the thermoplastic elastomer obtained by the dynamic heat treatment method, and this polyethylene resin has a melt index (190°C) of about 0.1 to 100.
Any one of high density to low density may be used. Polyethylene resin: 10 per 100 parts by weight of thermoplastic elastomer
It is added and kneaded in a range of 100 parts by weight. If it is less than 10 parts by weight, the addition effect cannot be exhibited and the improvement in calender formability is insufficient, and if it exceeds 100 parts by weight, the elastomer properties decrease and the calender formability does not improve.

Addition and kneading methods include blenders, extruders,
A method of melt-kneading using a mixing roll, kneader, Banbury mixer, etc. is used.

Furthermore, in the above method, peroxide non-crosslinked hydrocarbon rubber such as polyisobutylene, butyl rubber, propylene, ethylene (molar ratio about 90/10 to 50/50) copolymer rubber is added as an optional component, for example, during dynamic heat treatment. Alternatively, they can be blended at any other stage.

The thermoplastic elastomer composition used in the present invention may also contain rubber pigments such as carbon black, calcium carbonate powder, etc., as long as it does not impair moldability, elastomer properties, strength, weather resistance, durability, etc. Other pigments, colorants, fillers, known heat-resistant stabilizers, cold-resistant stabilizers, anti-aging agents, weather-resistant stabilizers, antistatic agents, etc. can also be blended.

In this way, the composition obtained by adding and kneading a predetermined amount of polypropylene resin to a thermoplastic elastomer can be smoothly formed into a sheet using a calendar while maintaining the desirable physical properties inherent to the thermoplastic elastomer. be effective.

Next, the present invention will be explained with reference to examples.

Example 1 Ethylene/propylene/5-ethylidene-2-
Norbornene ternary copolymer rubber [ethylene/propylene molar ratio 70/30, iodine value 15, Mooney viscosity ML ₁₊₄ (100°C) 70] 70 parts (weight, same below),
15 parts of polyisobutylene (Etsuo product, Vistanex MML-100), polypropylene [density 0.91
g/cm ³ , melt index (ASTM-D-
1238-65T, 230℃) 13] 15 parts, 30 parts of naphthenic process oil, and 1 part of erucic acid amide were heated at 180℃ in a nitrogen atmosphere using a Banbury mixer.
After kneading for 5 minutes, the pellets were passed through a roll and granulated using a sheet cutter. Next, the pellets and a solution prepared by dissolving and dispersing 0.3 parts of 1,3-bis(tert-butylperoxyisopropyl)benzene in 0.5 parts of divinylbenzene were kneaded using a tumbler blender, and the peroxide solution was applied to the pellet surface. It adhered evenly. Thereafter, the pellets were extruded at 210° C. under a nitrogen atmosphere using an extruder to prepare pellets of the thermoplastic elastomer composition.

Next, a melt index of 1 (190℃) and a density of 0.92 were added to 100 parts by weight of the pellets at a ratio of 30 parts by weight.
of polyethylene pellets were mixed.

After melting and kneading this mixed pellet in a kneader, it was then wound around two 8-inch diameter rolls (calender rolls) heated to 160-180°C and when the sheet was taken out from the rolls, the sheet stuck to the rolls. It was possible to easily pull out a uniform sheet with uniform thickness and no sag or wrinkles.

This shows that the sheet can be easily obtained by the calender molding method.

Comparative Example 1 In Example 1, the same procedure as Example 1 was carried out except that erucic acid amide and polyethylene resin were not blended, and calender formability was evaluated. However, the sheet stuck to the roll and could not be pulled out. Ta.

Claims (1)

[Claims] 1 Ethylene/α-olefin copolymer rubber (a) 90~
40 parts by weight, polypropylene resin (b) 10 to 60 parts by weight, total amount of (a) + (b) 100 parts by weight, mineral oil softener (c) 5 to 100 parts by weight, and (a) + ( A thermoplastic elastomer obtained by dynamically heat-treating a kneaded product of 0.05 to 3 parts by weight of higher fatty acid amide per 100 parts by weight of the total amount of b) + (c) in the presence of an organic peroxide, 10 to 100 parts by weight of plastic elastomer
1. A method for producing a thermoplastic elastomer composition sheet, which comprises adding and kneading 100 parts by weight of a polyethylene resin and calendering the composition.