DE4131437A1 - Plastic material, useful esp. for prodn. of aerosol valve-bodies - contg. ether]-amide] block copolymer and styrene]-butadiene elastomer - Google Patents

Abstract

Plastic material (I) contains up to 100 (pref. 40-95) wt.% polyether-amide block copolymer (II) and below 60 (pref. 20-5) wt.% styrene-butadiene (SB) elastomer (III). Pref. (I) contains 40-47.5 wt.% (II) with Shore hardness 45D and 12-5 wt.% (III), or 40-47.5 (pref. 44-46, esp. pref. 45) wt.% (II) with hardness 45D, 40-47.5 (pref. 44-46, esp. pref. 45) wt.% (II) with hardness 40D and 20-5 (pref. 12-8, esp. pref. 10) wt.% (III), pref. with hardness 40A. (III) can be replaced by chemically crosslinked elastomer(s), pref. polysulphide rubber. Mixts. (I) have good elastic properties combined with good resistance to solvents and are therefore esp. useful e.g. in gastight valves for 2-component aerosol cans contg. solvent-based materials. Pref., (II) are PA-6 elastomers or polyether-ester-amides. Valve body is injection moulded. A mixt. of 45 wt.% (II) (Shore hardness 45D), 45 wt.% (II) (hardness 40D) and 10 wt.% SB elastomer was injection moulded to form a valve body, which was then combined with a valve head and mounted in an aerosol can be filled with a propellant gas. The valve had release pressure, 55N; solvent swelling (wt. increase), 3.8, 14.9, 17.4% (in acetone, CH2Cl2 and trichlorethylene respectively); loss of gas (10 days at 50 deg. C), 0.088 g/day. USE/ADVANTAGE - (I) is useful for the prodn. of valve bodies for aerosol containers. valve bodies can be made of (I), pref. in one piece, esp. for use in multi-component aerosol containers, and aerosol containers, esp. as above, with valve bodies contg. (I).

Description

The invention relates to a plastic material for the production of intended for use in devices - built-in parts, in particular of Valve bodies for valves and the use of the Plastic material.

In the operational - especially the chemical and cosmetic - practice There is often a desire for solvent resistant and therefore flexible and easily movable components. For example, you search Such built-in parts as a valve body in valves of pressure vessels such as in aerosol cans.

For example, aerosol containers have been used for several years Packaging of multi-component polyurethane systems used, such as they are used in the construction industry.

For the needs of the cosmetics industry such containers are little or not at all suitable, since in particular the valve mechanism thereby used chemicals is not grown. Above all, the previously used valve body too low Lösungsbe durability - for example, against acetone, methylene chloride, trichlorethylene od. Like. - on, if they should be sufficiently elastic. In addition, in particular for conventional spray cans - such as for a multi-component system, in which always at least two valves are operated simultaneously - the Release force of the valve remain low for reasons of ease of use, preferably below 30 N lie. In addition, a valve body with the assigned to him a seat i.w. gastight mating revealed to Avoid gas losses wherever possible.  

Object of the present invention is to provide a plastic mixture for To make available, which allows mounting parts of device and in particular to produce valve bodies of valves, the solvent resistant, have a low gas loss and easy to use.

To solve this task lead the teachings of the independent Claims. Thus, according to the invention, a plastic material or a plastic mixture containing up to 100 wt .-%, preferably about 40 to 95 wt .-%, at least one polyether block and up to about 60% by weight, preferably 20 to 5% by weight, of a styrene-butadiene Elastomers offered.

Suitably, the plastic mixture contains 88 to 95 wt .-% of a Polyether block amides with a Shore D hardness of 45 and 12 to 5 wt .-% a styrene-butadiene elastomer (Shore A hardness of 40 °). Prefers is a plastic mixture containing 40 to 47.5 wt .-% of a such polyether block amide a Shore D hardness of 45; 40 to 47.5 % By weight of a polyether block amide having a Shore D hardness of 40 and 20 to 5 wt .-% of a styrene-butadiene elastomer.

A plastic mixture containing 44 to 46% by weight is advantageous. a polyether block amide with a Shore D hardness of 45, 44 to 46% by weight a polyether block amide having a Shore D hardness of 40 and 12 to 8% by weight a styrene-butadiene elastomer.

Particularly preferred is a plastic mixture containing 45 wt .-% of a polyether block amide having a Shore D hardness of 45.45% by weight Polyetherblockamids a Shore D hardness of 40 and 10 wt .-% of a Styrene-butadiene elastomer.  

According to another feature of the invention have used Polyetherblockamide - as already mentioned - a Shore D hardness of 45 Degree or Shore D hardness of 40 degrees, each measured according to DIN 53 505.

The polyether block amides may be ether-amide elastomers act. Ether-amide elastomers - and in particular the Block polymers - exist within a chain of alternating and sufficiently long hard and soft segments. The Elastomeric properties come through the interaction of these chains between each other.

The elastomeric properties can be determined by physical, chemical or physical and chemical crosslinking can be achieved.

Polyether block amides are, for example, based on polyamides Caprolactam and the experts also known as PA-6 elastomers. Also preferred are polyetheresteramides.

In the styrene-butadiene elastomers - preferably those of a Shore hardness A of 40 °, measured according to DIN 53 505 - is the matrix such Block copolymers of a mass fraction of, for example, about 60% made of elastomer, such as. B. of rubbery segments of Polybutadiene, and the physical crosslinks with a Mass fraction of about 2 · 20% consist of polystyrene, in the form two terminal blocks is chemically bonded to the elastomer.

A particularly favorable solvent resistance is, for example, with a blend of about 90% by weight of a polyether block amide of Shore Hardness D of 45 and about 10% by weight of a styrene-butadiene of a shore Hardness A reaches 40. The triggering force is relatively high, the average swelling is 11% with low gas loss.  

The release force is at a mixture of about 45 wt .-% of Polyetherblockamides mentioned above and about 45% of a further polyether block amides of Shore D hardness of 90 and 10% by weight Styrene butadiene Shore hardness A of 40 optimal, the average Swelling is 12%. Here, the gas loss is higher than in the aforementioned Example.

The thermoplastic elastomers (TPE) used can be used for Improved aging resistance to be stabilized. you will be mainly on injection molding machines with hot cylinder and cold Tool processed - like ordinary thermoplastics.

In addition to the thermoplastic elastomers (TPE) are also chemically crosslinked elastomers used on an injection molding machine with cold cylinder and hot tool are processed as the material chemically irreversibly crosslinked (vulcanized) must be.

As materials for the above-mentioned inserts can here for example:

• - treated natural rubber (NR);
• - cis-1,4-polyisoprene;
• Styrene-butadiene rubber;
• - Cis-1,4-polybutadiene;
• Butyl rubber;
• Ethylene-propylene terpolymer;
• Ethylene-VAC copolymer;
• - polychloroprene;
• - nitrile rubber;
• - urethane rubber;
• - polysulfide rubber;
• - acrylic ester rubber;  
• - epichlorohydrin rubber;
• - Chlorosulfonated polyethylene;
• - fluoro rubber;
• - silicone rubber;
• - Cyclo rubber.

The rubbers show hardness up to Shore 90 A (according to Shore 38 D) So, in general, are very soft as well as with valve body few exceptions (eg polysulfide rubber) bad solvent resistant. Compared to the thermoplastic elastomers is the Use of chemically crosslinked elastomers unfavorable, so may Worsened solution considered the task seen by the inventor become.

The plastic mixtures according to the invention are for the production of Valve bodies in valves of aerosol containers particularly suitable. Therefore, the present invention also encompasses such valve bodies from or containing said plastic mixtures, these Valve parts can find application in aerosol cans, especially at Valve bodies for multi-component aerosol containers.

Accordingly, the invention also relates to aerosol containers with valves, the valve body of the plastic mixtures according to the invention exist or contain these. Preferably, the insert is in the Component aerosol containers - as for example as a pressure vessel for gases, liquids, pasty products od. The like. Known and about in EP-B 01 11 089 are described - and especially as one-piece Valve body, which are produced in particular by injection molding. Such valve bodies may be parts of in a common valve plate sitting exhaust valves, each with a pressure chamber in combination stand and - also together by a in the axial direction slidable, radially immovable and against axial pivoting secured guided release member can be actuated.  

Valve groups of this known type are operated together, including also a pivotally mounted lever member can be used, its pivot axis parallel to a through the center of the valve body laid straight line runs.

In addition, the use of the preferred is within the scope of the invention Plastic mixture for valve parts of aerosol cans. expedient Plastic mixtures, as well as advantageous valve parts of aerosol cans for the said uses are described above.

Further advantages, features and details of the invention will become apparent also more preferred from the description below Embodiments.

• 1. The following mixtures are prepared and sprayed into valve bodies:
  • a) 95% by weight of polyether block amide Shore D 45+ 5% by weight of styrene-butadiene elastomer
  • b) 92.5% by weight polyether block amide Shore D 45+ 7.5% by weight styrene-butadiene elastomer
  • c) 90% by weight polyether block amide Shore D 45+ 10% by weight styrene-butadiene elastomer
• 2. The sprayed valve bodies are inserted into a valve holder and this is assembled with a valve plate. The whole Assembly group is then connected to an aerosol can and with filled with a propellant gas.
• The force which leads to the escape of the propellant gas when the valve is actuated is called the tripping force. Valve body of the mixture Tripping force N a) 80.4 b) 71.4 c) 69.7
• 3. The swelling behavior is determined on the valve bodies. For this purpose, samples of valve bodies of certain diameters are placed in various solvents for 24 h and the degree of swelling is determined by comparing the dimension and degree of swelling and calculating the increase in%.
• 4. To measure the gas loss as in Example 2 with propellant gas filled aerosol cans and the aerosol cans for 10 Days at 50 ° C stored. The gas loss is determined by the determination Weight loss of aerosol cans measured by weighing.
• 5. The following mixture is prepared and sprayed into valve bodies: Valve body of the mixture Loss in 0.01 g / d (grams / day) a) 7.0 b) 6.8 c) 6.4
• 5. The following mixture is prepared and sprayed into valve bodies: 45% by weight of polyether block amide Shore hardness D 45
  45% by weight of polyether block amide Shore hardness D 40
  10 wt .-% styrene-butadiene elastomer

The valve bodies are according to Example 2 on the tripping force tested, with a release force of 55 N is determined.

When determining the swelling behavior, the test method becomes weaker Example 3 used. The increase in the swelling in acetone is 3.8%, in methylene chloride at 14.9% and in trichlorethylene at 17.4%. The gas loss, measured according to the test method according to Example 4, is 8.8 measured in 0.01 g / d.

Claims (12)

1. plastic material for the production of movable solvent-resistant and elastic mounting parts, in particular those that with a counter element i.w. gas-tight mating form containing up to 100 wt .-%, preferably about 40 to 95 Wt .-%, at least one polyether block amide and less than 60 wt .-%, preferably 20 to 5 wt .-%, of a styrene-butadiene elastomer. 2. Plastic material according to claim 1, containing 88 to 95 wt .-% a polyether block amide with a Shore D hardness of 45 and 12 to 5 wt .-% of a styrene-butadiene elastomer. 3. Plastic material according to claim 1, containing 40 to 47.5 wt .-% a polyether block amide having a Shore D hardness of 45, 40 to 47.5% by weight of a polyether block amide having a Shore D hardness of 40 and 20 to 5% by weight of a styrene-butadiene elastomer. 4. plastic material according to claim 1, containing 44 to 46 wt .-% a polyether block amide having a Shore D hardness of 45, 44 to 46 % By weight of a polyether block amide having a Shore D hardness of 40 and 12 to 8 wt .-% of a styrene-butadiene elastomer. 5. Plastic material according to claim 1, containing 45 wt .-% of a Polyetherblockamids a Shore D hardness of 45, 45 wt .-% of a Polyether block amides with a Shore D hardness of 40 and 10% by weight a styrene-butadiene elastomer.   6. plastic material according to one of claims 1 to 5, characterized characterized in that the styrene-butadiene elastomer has a Shore hardness A has about 40. 7. plastic material for the production of movable, Solvent-resistant and elastic built-in parts, the in particular with a counter element a i.w. gas-tight mating form, containing at least one chemically crosslinked elastomer or consisting of at least one chemically cross-linked Elastomer. 8. plastic material according to claim 7 containing Polysulfide. 9. Valve body for a valve made of a plastic material at least one of claims 1 to 8 or contains and preferably integrally molded. Valve body for a valve for use in an aerosol container, especially in a multi-component aerosol container, containing one or consisting of a plastic material after at least one of claims 1 to 8. 11. aerosol container, in particular multi-component aerosol container, with at least one valve body made of or with art Fabric materials according to at least one of claims 1 to 8. 12. Use of the plastic mixture according to at least one of Claims 1 to 8 for valve body of aerosol containers.