JPS6011982B2 - film composite material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to elastic block polymer films having tack-free properties.

More particularly, the present invention relates to formulation components for packaged vulcanized rubber and green rubber packaged with said film. The invention further relates to cured or vulcanized rubbers produced with said components. Films of many unvulcanized block copolymers, such as styrene-butadiene-styrene block copolymers, tend to stick to each other when stacked or rolled, ie, develop mild sticking.

This blocking or sticking phenomenon causes troublesome problems and leads to difficult situations that cannot be ignored. For example, stacks of unvulcanized rubber bales wrapped in the film cannot be separated without breaking or tearing the film. The film pieces remain stuck to the rubber. In general, those skilled in the art continue to strive to increase the storage capacity of unvulcanized rubber. Recovery temperature
It is desirable to substantially reduce or eliminate the tackiness of undoped dilute styrene-butadiene-styrene block polymers in films and sheets.

Commonly used anti-blocking agents that can be blended with the block polymers mentioned above include various waxes, soaps, silicones, pigments, vegetable lecithins alone or in combination, stearyl erucamide, and oleyl. and specific mixtures of palmitamide and behenamide.
However, when packaging hot-formed rubber at temperatures above 1800F (800F) and effectively preventing the unvulcanized rubber packages from sticking together or sticking together, the anti-blocking agents described above may be used. It is particularly unsatisfactory for extrusion films of unvulcanized styrene-butadiene-styrene block polymers. Accordingly, it is an object of the present invention to provide a formulated elastic block copolymer film having tack-free properties and products packaged with the film.
A film composition having anti-tack properties can be obtained using the following general composition A.
-B-A, where each A is a separately selected inelastic monovinyl aromatic compound having an average molecular weight of about 7,000 to about 25,000 and a glass transition temperature of about 25 qo or greater selected from styrene, Q-methylstyrene, and vinyltoluene. a hydrocarbon polymer floc with a total content of A blocks of about 12 to about 62 wt% of the copolymer; B of about 3
1,3-butadiene and isoprene having an average molecular weight of from 0,000 to about 100,000 and a glass transition temperature of less than about 10 qo.

) and about 0 according to ASTM #D-1238
．． (ii) 10 parts by weight of a raw elastic block cobolimer having a melt viscosity within the range of 1 night to about 10 nights/10 minutes; (ii)
Styrene, 0-methylstyrene, styrene/Q-methylstyrene, vinyltoluene, vinyltoluene/Q-methylstyrene, indene resin, alkylphenol resin, petroleum resin, coal tar resin, and 'a' approx.
about 100 parts by weight of polystyrene having a molecular weight in the range of from 0.00 to about 50,000; from about 25 to about 12 parts by weight of a thermoplastic resin selected from at least one polymer of high impact polystyrene, comprising from about 3 to about 3 parts by weight, preferably from about 3 to about 1 parts by weight; and (iID A.S.
Approximately 1900F (approximately 88
It has been discovered by the present invention that the wax can be obtained from a mixture with about 0.5 to about 1 part by weight of a hydrocarbon paraffin wax having a freezing point within the range of about 2200F (105C).

The film composition preferably has a thickness of about 0.5 to about 20 mils, more preferably about 1 to about 10 mils.

The film composite material may contain various typical thickeners,
It can contain fillers, pigments, extenders, stabilizers, etc. Elastic block copolymers useful in the practice of this invention for packaging rubber or various compounding ingredients are of the radial or linear type.

Generally, linear styrene-butadiene-styrene block copolymers are desired. The thermoplastic resin composition of the present invention is typically in the form of a film having a thickness of about 0.5 to about 10 mils and is tested in the tack-free test no. 2, it is characterized by having a tack-free property of about 0 to about 10 degrees.

Generally, radial type block copolymers are AB
Produced by coupling block copolymers with polyfunctionalizing agents. In general, linear type block copolymers can be produced by any method commonly used for producing block copolymers of styrene and butadiene.

For example, {1} production by first forming "living" polystyryllithium from styrene and alkyl lithium and then adding it to a styrene-butadiene mixture; '2} lithium metal or dilithium alkyl ( (e.g., tetramethylene dilithium). All of these are known to grow polymer chain chains; '3) by producing polystyryllithium, followed by polymerization of butadiene and then styrene; or'
It can be prepared by methods such as those prepared by polymerizing 41-butadiene with polystyryllithium and coupling with coupling agents well known to those skilled in the art. Thermoplastic aromatic resins useful in making the films of the present invention are preferably styrene, Q-methylstyrene, Q-methylstyrene/vinyltoluene, Q-methylstyrene/styrene, vinyltoluene, indenes, modified phenolic resins, petroleum and Aromatic resins selected from at least one of the monomer resins derived from coal, in toluene at a temperature of 30° C. from about 0.02 to
It is characterized by having an intrinsic viscosity of about 0.50.

It has been discovered that high impact polystyrene is particularly useful in the production of extruded compounded films. Generally, the aromatic resins are produced by conventional polymerization techniques well known to those skilled in the art.

High-impact polystyrene is produced by conventional methods and is usually
'a: about 10 parts by weight of polystyrene having a molecular weight within the range of about 15,000 to about 50,000; and 'b} selected from at least one of polybutadiene, polyisoprene, and butadienostyrene copolymers dispersed in the polystyrene. from about 5 to about 2 parts by weight of the elastomer.

In the practice of this invention, the styrene-butadiene-styrene block polymer/resin blend composition can be prepared by extrusion or solution casting.

Extrusion methods are usually preferred. This is because it is more advantageous in terms of processing economics, has greater versatility in manufacturing (flat film method or concentrator method), and because extrusion methods do not use solvents, there are fewer health problems and dangers. In the solution casting process, the block polymer and thermoplastic resin blend is typically dissolved in an organic solvent at a temperature in the range of about 4,000 to about 80 qo, and the solution is then mixed with a specific wax. do.

Desirably, the resulting mixture is cast onto a support in the form of a film, and the organic solvent is evaporated and dried to produce the desired composition in the form of a film. Next, the film is peeled off from the casting support. Typically, the mixture will contain from about 40 qo to about 150 qo depending primarily on the organic solvent used.
It can be dried at a temperature of qC. When the composition is dried as a film, substantially lower temperatures and shorter drying times can be used. For example, about 70qo to about 9bi0
The drying process can be carried out at a temperature within the range of about 15 to about 6 minutes. When produced by extrusion methods, the following techniques can be advantageously used.

The composition is melted in a conventional extruder, preferably one with a length to diameter ratio of 2 $ to 1. The melt is passed upwardly through a circular die to produce "blister". This "blister" is then crushed in a cooling tower. The compressed "blister" can be slit to produce a single web, or left unslit as a compressed tube. The film or tube is then wound into rolls of specified length and width on conventional winding equipment. Unvulcanized rubber can be easily packaged according to the present invention.

Typical examples of various unvulcanized rubbers are natural rubber, synthetic rubber,
Rubbery polymers of 4-polyisoprene, 1,3-butadiene, rubbery copolymers produced by emulsion or solution polymerization of butadiene-styrene, and copolymers of butadiene and acrylonitrile. All of the rubbers mentioned above are of the highly unsaturated type. That is, the rubbers contain a considerable amount of carbon-carbon double bonds in their molecules. Although this invention relates in part to the packaging of highly unsaturated types of rubbers, low unsaturated types of rubbers can be packaged as well if desired. Typical examples of such low unsaturated rubbers are rubbery turbolimers consisting of ethylene, propylene and small amounts of conjugated hydrogen. Representative examples of non-conjugated genes include, for example, 1,4-hexadiene, dicyclobentadiene, and 2,5-ethylidenebicycloheptene. Various rubber compounding resins and compounding ingredients, particularly resins such as hydrocarbon resins, may also be packaged according to the invention and
It can then be blended with unvulcanized rubber.

Typical examples of various formulation ingredients are fillers such as clays, silicates, calcium carbonate, etc.; undesirable accelerators such as cadmium diethyldithiocarbamate, tetramethylthiuram disulfide, benzothiazyl disulfide, etc. ; antioxidants such as the well-known substituted phenols, substituted thioesters and amine types; antiozonants such as aniline derivatives, diamines and thioureas; sulfur, sulfur-available compounds and peroxides; curing agents such as substituted penzotriazoles and substituted penzophenones; colored pigments such as iron oxide, titanium dioxide, and organic dyes; carpon black, zinc oxide, and hydrated silica compounds. reinforcing pigments such as polyethylene, silicon dioxide, pumice, and processing aids such as stearate. The non-stick property of the composite film of the present invention for film production is such that the packaging materials do not stick to each other when they are deposited together or "containerized" and then stored at high temperatures. It is particularly useful for allowing the packaging material to be separated into virtually individual pieces without causing actual damage to the packaging material and the packaging material.

A further advantage is the increased protection against oxidation of the surface wax. The importance of discovering this effect will be explained in detail below. Polyethylene film (PE) is commonly used in rubber packaging bales to facilitate handling and use of the rubber.

In most applications, packaging bales are used as is. During processing, such as in Banbury mixers, rolling machines, calenders, tire manufacturing operations, etc., in many cases the PE packaging remains as discrete bits of film. That is, it has been determined that PE bits form void areas that break the rubber/rubber contact, leading to defects in the final product with respect to burst pressure, mechanical weakness, and other related issues. PE is not compatible with typical rubbers, and as a result, non-dispersed particles are foreign
It remains as ea). Similarly, it is known that PE does not cure into, or become part of, a rubber matrix. However, the composite films of the present invention with additional high structural stability are soluble in styrene and can be dispersed into rubber compounding components during normal mixing steps and can be cured together with the rubber matrix. .

Due to its technical advantages, the film composite of the present invention can be used for unvulcanized rubber in cases where {1} dispersibility, (2) co-curability with rubber or glue styrene solubility are required. It can be easily used for various compounding classifications and packaging of various plastics.

According to the invention, therefore, a package of unvulcanized rubber, especially a package of vulcanized rubber, such as a highly unsaturated rubber as mentioned above, and a package of unvulcanized rubber, especially for storage purposes, are according to the invention. consisting of vulcanized rubber substantially wrapped in a film composite wrapping material.

Indeed, the present invention is particularly useful for storing large raw rubber bales. The term "wrapping material" means a film applied to unvulcanized rubber, especially bales. When packaging bales, a two-sheet film can be advantageously used. One sheet is applied to the top of the bale and another sheet is applied to the bottom of the bale. The sheet is then wrapped around the sides of the shelf and heat sheeted together around the perimeter. Furthermore, the present invention provides a process for compounding rubber comprising a mixing operation and a corresponding compounded rubber comprising a resulting mixture containing a sulfur-cured mixture. The method comprises mixing unwashed rubber, in particular the above-mentioned packaged highly unsaturated rubber packaged in the film composite of the invention, and conventional compounding components, in particular the components packaged in the film composite of the invention, followed by It consists of vulcanizing said product mixture, optionally consisting of rubber, packaging film and packaged components. The present invention will be explained in more detail below with reference to Examples.

The following examples are merely illustrative of the invention and are not limiting. All parts and percentages are by weight unless otherwise specified. Example 1 Unvulcanized styrene-butadiene-styrene block polymer, high impact polystyrene, wax and other ingredients are mixed and the flowable formulation is extruded to produce a film approximately 5 mils thick. The film of this example was produced by the following steps.

The detailed composition of the film is shown in Table 1 below.

Table 1 Ingredients Partial styrene/butadiene/styrene block copolymer '1' 65.0
Impact resistant polystyrene'2) 35.0
Synthetic hydrocarbon wax '3} 5.0
Stearic acid (lubricant) 0.25 Polyethylene (solvent) (4} 0.50 Antioxidant 1.0○}
Solprene 41 from Philips Vetroleum
S-mo block copolymer '2, commercially available as 4
High-impact polystyrene commercially available from Dow Chemical Company as St〆on 475u {3' Synthetic with a freezing point in the range of about 200-2100F (93-100oo) commercially available as PawflintHl-NI from Moore & Munger Company Hydrocarbon Wax ■ Low molecular weight polyethylene, commercially available as EpoleneCIO-P from Eastman Chemical Co. Unvulcanized polybutadiene wrapped in this film is heated in three layers on each package for at least 7 hours at a temperature of 1900 F. It has been observed that even after pound packaging racks have been piled up, they can be separated into pieces with relative ease.

Further in accordance with the present invention there is provided polystyrene, particularly high-impact polystyrene, and a method for making the same.

In their implementation, packaging rubber, especially rubber packaging such as polybutadiene or styrene/butadiene copolymer (SBR), is packaged according to the invention using unvulcanized film composite packaging, and the packaging is placed in styrene monomer. The styrene solution is polymerized by methods well known in the styrene polymerization art using a free radical catalyst, such as a peroxide catalyst. The desired product, ie high-impact polystyrene, is comparable in its manufacture to the specifications of high-impact polystyrene produced without the use of the film wrapping material of the present invention. The polystyrene and its manufacturing method will be explained below with reference to Examples.

Parts and percentages are by weight unless otherwise specified. Example 2 Impact resistant polystyrene was produced as follows.

Ten parts of rubbery polybutadiene packaged in unvulcanized styrene/butadiene/styrene film of the type used in Example 1 were added to 1546.6 parts of styrene monomer while stirring in a suitable container.

The solution was stirred until a homogeneous mixture was obtained. 1.02 parts of penzoyl peroxide and 0.14 parts by weight of mercaptan modifier were dissolved in parts by weight of styrene monomer 4 and added to the homogeneous mixture. After dispersing these components, the temperature was raised to 8,000 ℃, and concentration was continued for 4 hours while maintaining this temperature. temperature to 75
qC and maintained this temperature for 3 hours. The reaction mass was removed from the mixing vessel and placed in a closed vessel for 1 hour at 10,000 and 17 hours at 150oo. 5 parts by weight of stearic acid and 2 parts of alkylated aryl phosphate were evenly blended into the reaction mass.
In this example, 1.
Rubbers such as 4-polybutadiene, SBR and polybutadiene or graft interpolymers of polybutadiene or S mother block polymers can be used.

As a polymerization initiator, lauroyl/g-oxide, 2-
Azobis-isobutyronitrile, hydroxyheptyl peroxide, methyl ethyl ketone peroxide, caprylyl peroxide, acetyl peroxide, di-t-butyl peroxide, t-butyl perbenzoate and t-butyl peracetate or dicumyl Peroxide etc. can be used. In practicing the invention, the tack-free properties of the films produced according to Example 1 were tested by measuring the tack resistance or adhesion to the film itself.

Testing was conducted by placing two film samples on top of each other to form a square double ply specimen approximately 2 inches long on a side.

The specimen was sandwiched between two metal plates in a horizontal position and approximately 1.5 pounds per square inch of pressure was applied to the metal plates. The resulting assembly was heated to approximately 1900F (88qo)
The mixture was placed in a temperature oven for about 72 hours. The assembly was then removed from the oven and the film was tested for tack-tack by manually peeling the film off at an angle of about 1800°. A number of samples of different film compositions were tested and rated on three criteria: excellent, good and poor. As a result of this test, the film of this example showed no tendency to stick to each other and was evaluated as excellent. Although certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit or scope of the invention. .

Claims (1)

Claims: 1. A film composite material having a thickness of about 0.5 to about 10 mils, comprising: (i) the general configuration A-B-A, where each A is styrene, alpha-methyl; Separately selected inelastic monovinyl aromatic hydrocarbon polymer blocks selected from styrene and vinyltoluene having an average molecular weight of about 7,000 to about 25,000 and a glass transition temperature of about 25° C. or higher, the total content of the A block is about 12 to about 62 wt% of the copolymer; B is about 30,000 to about 10
An elastic conjugated diene polymer block selected from 1,3-butadiene and isoprene having an average molecular weight of 0,000 and a glass transition temperature of less than about 10°C. ) and ASTM No. 100 parts by weight of an unvulcanized elastomeric block copolymer having a melt viscosity within the range of about 0.1 g to about 10 g/10 min according to D-1238;
ii) (a) about 100 parts by weight polystyrene having a molecular weight within the range of about 15,000 to about 50,000; and (b)
) from about 25 to about 120 parts by weight of high impact polystyrene comprising from about 3 to about 15 parts by weight of an elastomeric polymer selected from at least one of polybutadiene, polyisoprene and polybutadiene/styrene copolymers dispersed in the polystyrene; and (iii) ASTM N
o. D-938-49, in a mixture with about 3 to about 10 parts by weight of a hydrocarbon paraffin wax having a freezing point in the range of about 88 DEG C. to about 105 DEG C.