JPS58160336A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To provide a thermoplastic resin compsn. having excellent environmental stress cracking resistance, thermal stability, etc., by melt-kneading a rubber-contg. styrene resin with a latex of a copolymer of an olefin monomer with a fatty acid vinyl ester monomer. CONSTITUTION:100pts.wt. solid rubber-contg. styrene resin (A) such as an acrylonitrile/butadiene/styrene resin is melt-kneaded with a latex (B) contg. 0.5- 40pts.wt. copolymer having a gel content of less than 50wt% and a solubility parameter of 8.8-9.7 obtd. by copolymerizing an olefin monomer such as ethylene or propylene, a fatty acid vinyl ester monomer such as vinyl acetate or vinyl formate and optionally a coplymerizable vinyl monomer such as styrene or acrylonitrile, by means of a Banbury mixer to obtain the desired thermoplastic resin compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to thermoplastic resin compositions containing rubber-containing styrenic resins that excel in environmental stress requirements and yet have improved thermal stability.

When rubber-containing styrenic resin comes into contact with chemicals under stress, cracks occur and, in severe cases, breakage is observed; this phenomenon is called environmental stress cracking, and is a It is well known that this phenomenon is significantly observed in drugs that do not have high solubility, such as alcohols, carboxylic acids, alkanes, and alkenes.

This phenomenon occurs even when no external force is applied to the resin molded product, when the molding distortion that remains inside the molded product is released by contact with chemicals. Restrictions on multiple dogs are given.

The content of the rubber component and the molecular weight of the resin component are known to be factors that influence the environmental stress requirements of rubber-containing styrenic resins. Although the environmental stress requirements have been improved by increasing the pressure, the effect has not been sufficient for practical use.

By the way, JP-A-56-478 discloses a copolymer latex of an olefin monomer, a fatty acid vinyl ester monomer, and in some cases a vinyl monomer copolymerizable with this name, and a rubber-containing styrene resin. It is disclosed that by mixing both the resin and the latex in the latex state, a resin with significantly improved environmental stress requirements can be obtained.

Although the environmental stress requirements can be improved using the M method, nonionic high molecular weight surfactants are used when producing copolymer latex, that is, when emulsion copolymerizing monomers such as fatty acid vinyl esters. In this case, it is difficult to precipitate the resin from the mixture of copolymer latex and rubber-containing styrenic resin latex, and a large amount of inorganic acid and/or water-soluble inorganic salt must be administered. Not only is this disadvantageous, but it is also undesirable because a large amount of precipitating agent remaining in the resin recovered from the latex has an unfavorable effect on the thermal stability of the resin.

The present invention aims to improve this drawback.

That is, the present invention comprises: (Al) 10 parts by weight of a rubber-containing styrenic resin in a solid state; (B) an olefin monomer and a fatty acid vinyl ester monomer containing 0.5 to 40 parts by weight of a copolymer; or a latex of a copolymer of an olefin monomer, a fatty acid vinyl ester monomer, and a vinyl monomer copolymerizable with these monomers. The polymer has a rle content of less than 50%,
The thermoplastic resin composition is characterized by having a solubility parameter in the range of 8.8 to 9.7.

That is, according to the present invention, there is no need to precipitate the copolymer latex of the Bl component, which is difficult to precipitate, so the manufacturing process is simplified, and moreover, the amount of money spent on precipitating the copolymer of the component (B) is reduced. Because it does not require the addition of a large amount of precipitating agent, which previously had been used, the poor thermal stability of the resin due to residual precipitating agent is reduced, making it a rubber-containing styrene-based resin that meets environmental stress requirements and has improved thermal stability. resin can be provided.

The monomers constituting the rubber component of the rubber-containing styrenic resin with <A+ acid component of the present invention include conjugated diene monomers such as putazoene, isoprene, zomethylputazoene, chloroprene, and cyclopentadiene; Non-conjugated diene monomers such as 5-norbornadiene, 1,4-cyclohexadiene, 4-ethylidene norbornene, styrene, α
- Styrenic monomers such as methylstyrene, acrylonitrile, methacrylate trile, methyl methacrylate,
These monomers include (meth)acrylic monomers such as ethyl acrylate, butyl acrylate, hexyl acrylate, and octyl acrylate, and olefin monomers such as ethylene, propylene, 1-butene, isobutylene, and 2-butene. Specific examples of rubber components include polybutadiene, polyisoprene, polychloroprene, polybutyl acrylate, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, and butadiene. -Styrene-methyl methacrylate copolymer, ethylene-zoropyrene-4-ethylidenenorbornene copolymer, ethyl acrylate-butyl acrylate copolymer, etc., but are not limited to these. Additionally, a polyfunctional vinyl monomer can be copolymerized during the polymerization of these rubber components;
, 1.3-gutylene gelicoldimethacrylate, 1,
4-gutylene gelicol dimethacrylate, propylene glycol dimethacrylate, triallyl cyanurate,
Examples include triallyl incyanurate, trimethylolpropane trimethacrylate, allyl acrylate, allyl methacrylate, vinyl acrylate, vinyl methacrylate, glycizol acrylate, and glycidyl methacrylate.

The method of polymerizing these monomers is not particularly limited, and known techniques such as emulsion polymerization and solution polymerization may be used.

(The rubber component in the resin of the Al component does not need to be one type, and may be a mixture of two or more types of rubber components.

Monomers constituting the resin component of the rubber-containing styrenic resin (which is the Al component) of the present invention include styrene monomers such as styrene, α-methylstyrene, and vinyltoluene;
Acrylonitrile, methacrylonitrile, methyl methacrylate, ethyl acrylate, butyl acrylate,
Hexyl acrylate, octyl acrylate, etc. (
There are meth)acrylic monomers, etc., which are used in homopolymerization or copolymerization, but in order to obtain good moldability, it is essential to contain at least 65% by weight of styrene monomers.

(7) Component (A) used in the present invention is composed of a rubber component and a resin component as described above, but a graft structure is present at the interface between the rubber component that has a spherical structure and the resin component that is a continuous phase. It is necessary that the It is known that such a structure can be achieved by a so-called graft polymerization method in which part or all of the monomers constituting the resin component are polymerized in the presence of a rubber component. It can be manufactured using known graft polymerization techniques.

having a graft structure (in order to adjust the content of the rubber component contained in the Al component, it is also possible to mix a separately polymerized resin component with the (A) component, or a resin component that is not separately polymerized) The resin component does not need to have the same composition as the resin component obtained by graft polymerization.

For example, acrylonitrile in the presence of polybutadiene
A resin component obtained by copolymerizing acrylonitrile-styrene-α-methylstyrene can be mixed with the Al component obtained by graft polymerization of styrene-methyl methacrylate.

The resin used in the present invention (Al component is 2 to 60% by weight, (
8) It is preferable that the rubber component preferably has a weight ratio of 5 to 25. If the rubber component is less than 2% by weight (Al component, the effect of improving the environmental stress requirements of the resin obtained by mixing with the copolymer of component (B) is insufficient, and if the rubber component exceeds 60% by weight) This is undesirable because the rigidity and moldability deteriorate.

Specific examples of component (A) of the present invention include AES (acrylonitrile-butadiene-styrene) resin, side heat A
BS (acrylonitrile-butadiene-styrene-α
-methylstyrene) UL AAS (acrylonitrile-acrylic acid ester-styrene) resin, Z, O
S (acrylonitrile-chlorinated polyethylene-styrene) mUL AES (acrylonitrile-EPD
M-styrene) resin,
butadiene-styrene) resin, etc.

The comonomer of the Bl component used in the present invention is a copolymer of an olefin monomer, a fatty acid vinyl ester monomer, and in some cases, a vinyl monomer copolymerizable with these monomers. Although it is a polymer, the olefin monomers mentioned here include ethylene, propylene, 1-butene, 2-butene, isobutylene, cyclopentene, cyclohexene,
The fatty acid vinyl ester monomers include vinyl oxate, vinyl acetate, vinyl butyrate, vinyl trimethyl acetate, vinyl chloroacetate, etc., and can be co-electrified with these monomers. Other vinyl monomers include styrene monomers such as styrene, α-methylstyrene, vinyltoluene, chlorostyrene, dichlorostyrene, t-butylstyrene, cyanostyrene, aminostyrene, hydroxystyrene, and chloromethylstyrene. Acrylonitrile, methacrylonitrile, methyl acrylate, methyl methacrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, 2
- (meth)acrylic monomers such as methoxyethyl acrylate, 2-hydroxyethyl acrylate, allyl acrylate, glycidyl methacrylate, vinyl chloride,
Halodanated olefin monomers such as vinylidene chloride, vinyl ether monomers such as methyl vinyl ether, ethyl vinyl ether, and phenyl vinyl ether, vinyl ketone monomers such as methyl vinyl ketone and phenyl vinyl ketone, and acrylamide monomers such as acrylamide and methacrylamide. Examples include vinyl pyridine, N-vinylcarbazole, and the like.

If necessary, polyfunctional vinyl monomers can be used in combination with the above combinations. Examples of the polyfunctional vinyl monomer include ethylene glycol dimethacrylate, 1,6-butylene glycol dimethacrylate, 1,4-zotylene glycol dimethacrylate, propylene glycol dimethacrylate, triallyl cyanurate, triallyl incyanurate, and trimethylol. Examples include propane trimethacrylate, allyl acrylate, allyl methacrylate, and divinylbenzene.

(The B+ component is produced by emulsion polymerization and mixed with the Al component in a latex state. There are no particular restrictions on the emulsion polymerization method, and known techniques can be applied.

(The surfactant used in the emulsion polymerization of component B+ is not particularly limited, and anionic, cationic, nonionic, and amphoteric surfactants can be used alone or in combination, but they can be used to maintain emulsion stability during coagulation, foaming, etc.) In order to suppress the phenomenon, it is preferable to use a nonionic molecular weight surfactant in an amount of 5% by weight or more, preferably 20 weight % or more of the total amount of surfactant used.

However, the nonionic molecular weight surfactants mentioned here include polyzolopylene glycol ethylene oxide adducts, higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, fatty acid ethylene oxide adducts, aliphatic amine ethylene oxide adducts, Partially saponified polyvinyl alcohol, polyhydric alcohol fatty acid ester, etc.

There is no particular restriction on the solid content of the CB+ component latex, but (
During the dehydration process of the mixture, the solid content of the (B+ component latex) is set so that the water content in the mixture of the Al component resin and the (B+ component latex) is 50% by weight or less, preferably 60% by weight or less. This is preferable in consideration of operability.

The copolymer used in the present invention (B+ component has a gel content of 5
It must be less than 0.00% by weight. However, the gel content referred to here is determined by the following method. That is,
Add 1 g of polymer to ioog of methyl ethyl ketone and stir vigorously for 6 hours at room temperature. 150 of this stuff
Centrifuge at 00 rpm for 1 hour and determine the dry weight of the precipitate. The obtained dry weight is multiplied by 100 to obtain the gel content (% by weight).

When the component (E) is a copolymer having a gel content of 503ti% or more, the resin obtained by mixing the (Al component resin in a solid or molten state and the component (B) in a latex state). Improved fL with reduced impact strength and tensile strength
<No.

In addition, the copolymer (B+ component) used in the present invention must have a solubility parameter in the range of 8.8 to 9.7. However, the solubility parameter here is J
Using the solubility parameter values listed in the "Polymer Handbook" published by Ohn Wiley & 5ons, the solubility parameter δT of the copolymer is determined by determining the solubility parameter δT of the individual vinyl monomers constituting the copolymer consisting of m types of vinyl monomers. It is calculated by equation (1) from the solubility parameter δn of the homopolymer and its weight fraction wn.

For example, the solubility parameters of polyethylene, polyvinyl acetate, and polyglutyl acrylate are listed in 8.1.9.
4.8.8, the solubility parameter δT of a copolymer consisting of ethylene weight percent, vinyl acetate 70 weight fl and butyl acrylate 15 weight percent is calculated to be 9.1. (If the solubility parameter of the B+ component deviates from the above range, the impact strength, tensile strength, and environmental stress of the resin obtained by mixing the (Al component in a solid or molten state and the (B) component in a latex state) This is undesirable as it lowers the safety requirements.

As mentioned above, the gel content and solubility parameter of the copolymer (B+ component) are limited, but the composition ratio of the copolymer is arbitrary within the range that satisfies the above limitations.

In the present invention, % (100 parts by weight of Al component resin and 0.5 to 40 parts by weight, preferably 2 to 30 parts by weight of a copolymer of component (B))
However, if the amount of the Bl component copolymer added is less than 0.5 parts by weight, the effect of improving the environmental stress requirements of the resin obtained by mixing with the Bl component copolymer is sufficient. Not 40
If the amount exceeds 1 part by weight, the effect not only becomes saturated, but also the rigidity decreases, which is not preferable.

In the present invention, it is not necessary to precipitate the (B) component latex by adding a precipitating agent (during the process of mixing the Al component and the (B) component, and before and after that). That is, (a)
Resin in solid state (Al component) and latex state (Bl
A method of producing a composite resin by pre-mixing the component copolymer with the component copolymer at a temperature lower than the melting temperature of the component resin (A) and then supplying the mixture to a melt mixing device; The composite resin can be easily produced by a method of producing a composite resin by supplying the resin and the copolymer of component (B) in a latex state to a melt mixing device without mixing them in advance.

In the manufacturing method of U) above, the mixing device used for pre-mixing at a temperature lower than the melting temperature of the resin of the Al component may be a mixing device that is not used for mixing solid particles such as powder, granules, etc. Specifically, Henschel mixers, super mixers, ■-type mixers, tumblers, ribbon blenders, etc. are used, but a straw mixing device is heated at a temperature lower than the melting temperature of component (A), and the ingredients contained in the mixture are heated to a temperature lower than the melting temperature of component (A). Part or all of the water that is left in the mixture may be removed by evaporation during the mixing process.

The melt-kneading device used in the manufacturing method of (a) or (b) above may be a known device used for melt-mixing of thermoplastic resins, and may be equipped with a dehydration mechanism for the purpose of removing water contained in the material to be melt-mixed. It is also possible to use a melting crosstalk device that is actively held. Specific examples include a Banbury mixer, an Intenjig mixer, a mix truder, a co-kneader, an extruder, and a roll, and the screws may be single or multi-screw. Active dehydration mechanisms include a mechanism that removes steam generated from the bathed melt-kneaded material at normal pressure or reduced pressure, and a mechanism that removes water squeezed out of the bathed melt-kneaded material from the system. 50-
17227, Japanese Unexamined Patent Publication No. 56-18604, Patent Application No. 55-3
4149, etc., as disclosed in each publication.

To exemplify the specific steps of the production method in (a) above, after mixing the solid state resin component (A) and component latex (B) in a Henschel mixer to obtain a wet mixture, this mixture is mixed in a vented extractor. There is a method of melt-kneading and pelletizing with a ruder, and to illustrate the pillow-like process of the manufacturing method (B), without mixing the solid state component (A) resin and component (B) latex in advance, There is a method of feeding the material to a vented kneader to melt and knead it, and then feeding it to a vented extruder to pelletize it, but this method combines two mechanisms: dehydration and melt mixing.
Compositions prepared by other contemplated vine manufacturing methods are also encompassed by the present invention.

This method does not require the precipitation operation of the CB+ component latex by adding a precipitating agent, which not only simplifies and saves energy in the manufacturing process, but also minimizes the amount of precipitating agent remaining in the final composition. The thermal stability of the final composition is improved. In this production method, a rubber-containing styrenic resin composition excellent in environmental stress requirements can be obtained by limiting the R content and solubility parameter of the Bl component copolymer to the above ranges.

Furthermore, the thermoplastic resin composition of the present invention may contain pigments, dyes, stabilizers, dispersants, additives, fillers, weathering agents, antistatic agents, foaming agents, lubricants, and the like.

As explained above, the compositions of the present invention are suitable for fatty acids,
It can be suitably used in areas that may come into contact with chemicals such as oils, fats, alcohol, and hydrocarbons, and conventional rubber-containing styrene resins have frequently caused environmental stress cracking when used in these areas. Considering this, its industrial value is enormous.

The present invention will be further explained below with reference to Examples, in which all parts and percentages are expressed on a weight basis.

Example 1 The Al component shown in Table 1 and the (B) component latex shown in Table 2 were charged into a Henschel mixer in the ratio shown in Table 3.
Furthermore, 0.75 part of ethylene gas stearamide, TNP
Add 0.5 part of (IJ-based stabilizer) to 1700 r
pm for 6 minutes. The contents were a moist, uniform powder, and almost no deposits on the inner walls of the Henschel mixer were observed.

Next, this wet powder was mixed with Toshiba Machine Co., Ltd. TEM-50 (
The mixture was fed to a co-rotating twin-screw kneading extruder) to obtain pellets. TFjM-50 incorporates one pent barrel and two slit barrels, operates at a barrel temperature of 220°C, one screw rotation speed of 80 rpm, and produces 60 to 80 kg/
The discharge amount of Hr was obtained. No foaming of the strands was observed;
No abnormality was observed in the appearance of the pellet.

Moldings were made from the obtained pellets and their physical properties were evaluated, and the results are shown in Table 6 Experimental Flats 1 to 11.

Example 2 The composition of Table 3 Experiment/1 was mixed in a Henschel mixer and then fed to a VC-40 (vented single screw extruder) manufactured by Chuo Kikai Seisakusho Co., Ltd. to obtain pellets. The extruder has a cylinder temperature of 220°C and a screw rotation speed of 60 rp.
Although the pellets were operated at a discharge rate of 12 kg/Hr, no foaming of the strands was observed, and no abnormality was observed in the appearance of the pellets.

Moldings were made from the pellets that were not obtained and their physical properties were evaluated, and the results are shown in Table 6 Experimental Flat 12.

Example 6 The fA) component powder and the (B) component latex having the same composition ratio as Table 6 Experiment S1 were supplied to a KI type experimental intermix (Banbury mixer) manufactured by Hitachi Taura Factory, Ltd. without being mixed in advance. The mixture was melt-kneaded in a bath. The Banbury mixer was heated to 140°C, first containing lubricant and Yasuya agent (Al component was added and kneaded, and when the internal temperature reached 210°C (Bl component latex was pressurized and kneaded for another 4 minutes) Mixing was continued.The contents were processed into a flat plate with a roll in the middle, crushed, and subjected to molding.Table 3 shows the physical property evaluation results of this sample.
This is shown in Experiment A13.

Example 4 (A) Component (A-4) or (A-5) at 91%
Samples were prepared in the same manner as in Example 6 except that 9 parts of (B-1) was used as the Bl component, and the results of evaluating the physical properties are shown in Table 6 Experiment/r; 14.15.

Example 5 The Tbu-50 feed barrel used in Example 1 was installed, and (Bl component latex was directly supplied into the cylinder by a pump. The (A) component was (A-1) 37.5
s, (A-6) for 53.5 m, mixed with 0.75 parts of ethylene bisstearamide, 5 parts of TNP Q, and 5 parts of TNP in a Henschel mixer, then charged into a hopper and discharged at a rate of 62 kg/Hr. I pushed it out.

In addition, (B-1) latex was used as the Bl component, and a fixed amount was supplied into the cylinder at a rate of 10 to 9/Hr (latex weight).

No foaming was observed in the obtained strand, and no abnormality was observed in the appearance of the pellet.

A molded article was made from the obtained pellet and its physical properties were evaluated, and the results are shown in Table 6 Experimental Flat 16.

Comparative example 1 (as Bl component (B-5), (B-8), (B-9)
A molded product was prepared in the same manner as in Table 3 Experiment S1 except that the physical properties were evaluated, and the results are shown in Table 4 Experimental Seat 17.1.
8.19.

Comparative Example 2 (A-1) 125 parts of latex (latex weight, solid content 30q/)) and (B-1) 16 parts of latex (latex weight) were mixed in a latex state, and 3
A slurry was obtained by adding 0.65 parts of 5th grade hydrochloric acid and 6.7 parts of calcium chloride and stirring at 93° C. for 5 minutes. The wet powder obtained by dehydrating this slurry contained 42% moisture, which was higher than the moisture content of 21 qb of the wet powder obtained by precipitating only latex (A-1) under the same precipitation conditions.

The wet powder after drying (A-6) 53.5 parts, 0.75 parts of ethylene bisstearoids, TNP O, 5f
Both were mixed using a Henschel mixer and pelletized using a single screw extruder.

Moldings were made from the pellets that were not obtained and their physical properties were evaluated, and the results are shown in Table 4, Test Flat 20.

In addition, when calcium chloride was quantified in the dry powder obtained by precipitating only latex (A-1), it was 660 ppm, or it was found to be 660 ppm. Calcium chloride in the dry powder was determined to be 4020 ppm.

Comparative Example 6 A boric acid aqueous solution was added to the (E+ component latex) in Table 2 (B-1) to precipitate a polymer, which was then dried to obtain (Bi component solid 9
parts, (A-1) 37.5 parts, (A-7S) 53.5 parts
part, ethylene bisstearamide 0.75m, TNP
3.5 parts and pelletized using a single screw extruder.

A molded article was made from the obtained pellet and its physical properties were evaluated, and the results are shown in Table 4.

Comparative Example 4 (37.5 parts of (A-1) as Al component, (A-6
) and 30 parts of (B-1) as the component (B).

A molded article was made from the obtained pellet and its physical properties were evaluated, and the results are shown in Table 4 Experimental Flat 22.

Comparative Example 5 Table 4 shows the physical property evaluation results of component (A) only.
．． 25.26.

In these tests, all physical property measurements were obtained by the following methods.

(1) Tensile yield point...ASTM D-
638 + 2) Fizot side + s strength, = ASTM D
-256 (3) Thermal stability test method The resin was placed inside the cylinder of a 2-ounce injection molding machine with a cylinder temperature of 250°C for 10 minutes, and then injection molded. The whiteness W0° of the flat plate) was determined by C0L manufactured by Nippon Denshoku Industries Co., Ltd.
O)l AND 0OLORDIFFERENCEME
'Measure using FERMODEL ND-1Q 1Do.

In addition, the whiteness Wo of a molded product injected without performing a residence operation using an injection molding machine under the same conditions is measured. Whiteness change rate W
Find D = (WOW15)/No x 100,
WD<10 is evaluated as A, 10<wD<2o as B% WD≧20 as O. With WD-n-20 resin, even if the molded product is injected without performing a residence operation, the Wo of the molded product will vary depending on the slight difference in molding temperature, which is not preferable.

(4) Environmental stress cracking test method JIS E80
R-EG) is applied and left at 23°C, the time to breakage is expressed in minutes.

Claims (1)

[Claims] 1. (Rubber-containing styrenic resin 10 in an Al solid state)
0 parts by weight, and a copolymer of an olefin monomer and a fatty acid vinyl ester monomer, containing 0.5 to 40 parts by weight of B1 copolymer,
Alternatively, a latex of a copolymer of an olefin monomer, a fatty acid vinyl ester monomer, and a vinyl monomer copolymerizable with these monomers is melt-kneaded, and each of the above copolymers contains a gel. Thermoplastic resin composition characterized in that the ratio is less than 50 parts by weight and the solubility parameter is in the range of 8.8 to 9.7. 2. Rubber-containing styrenic resin of (Al component) and (Bl
The thermoplastic resin composition according to claim 1, which is produced by mixing the component latex at a temperature lower than the melting temperature of the rubber-containing styrenic resin in advance and then melt-kneading the mixture in a bath. 6. The thermoplastic resin according to claim 1, which is produced by supplying the rubber-containing styrenic resin as the component (A) and the latex as the Bl component to a melt mixing device without mixing them in advance.