JPH0425532A - Expandable resin composition and its molded item - Google Patents

Abstract

PURPOSE:To obtain the title composition which can give a foam improved in moldability, heat resistance and chemical resistance by impregnating a resin composition comprising two specified copolymers with an easily volatile organic blowing agent. CONSTITUTION:An aromatic vinyl monomer (ii) is copolymerized with an unsaturated dicarboxylic acid imide monomer (iii) and a vinyl monomer (iv) copolymerizable therewith in the presence of optionally a rubbery polymer (i) to obtain an imidized copolymer (a) comprising 0-40wt.% component (i), 30-70wt.% residues of component (ii), 30-60wt.% residues of component (iii), 1-20wt.% residues of the unsaturated dicarboxylic acid monomer and 0-40wt.% residues of component (iv). 10-100wt.% component (a) is mixed with 90-0wt.% copolymer (b) comprising 40-90wt.% residues of an aromatic vinyl monomer, 0-40wt.% residues of a vinyl cyanide monomer and 0-40wt.% residues of a vinyl monomer copolymerizable therewith to obtain a resin composition (A). Component A is impregnated with 2-15wt.% easily volatile organic liquid blowing agent (B).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a developing resin composition having excellent moldability and heat resistance, and a molded article thereof.

[Conventional technology]

Conventionally, expanded polystyrene molded products made mainly from general purpose polystyrene (GPPS) and high impact polystyrene (HIPS) have been used as bottle covering materials, cup materials, various packaging materials, and construction materials by utilizing their cushioning and heat insulating properties. It is expected to be applied to various types of housings, etc.

[Problem to be solved by the invention]

However, these foamed polystyrene molded products are not satisfactory in terms of heat resistance and chemical resistance, and their uses are naturally limited.

As a result of extensive research, the present inventors developed a foaming resin composition consisting of a specific thermoplastic resin composition and an easily volatile foaming agent, and by foaming the resin composition, We have discovered a foam molded product with excellent moldability, heat resistance, and chemical resistance, and have completed the present invention.

[! Means to solve problem I]

That is, in the present invention, the prisoner component: 0 to 40% by weight of rubbery polymer.
, 30 to 70% by weight of aromatic vinyl monomer residues, 30 to 60% by weight of unsaturated dicarboxylic acid imide monomer residues, 1 to 20% by weight of unsaturated dicarboxylic acid anhydride monomer residues, and other than these. Component (B): 40 to 90% by weight of aromatic vinyl monomer residues, vinyl monomer cyanide monomer, and Copolymer 9 consisting of 0 to 40% by weight of monomer residues and 0 to 40% by weight of vinyl monomer residues copolymerizable with these tS
The present invention is characterized by a foamable resin composition obtained by impregnating a resin composition of 0 to 0% by weight with a readily volatile organic liquid blowing agent, and a molded article thereof.

First, the imidized copolymer of component A and its manufacturing method will be explained.

(As for the production method of the Al component copolymer, in the first production method, if necessary, in the presence of a rubbery polymer, an aromatic vinyl monomer,
A method of copolymerizing an unsaturated dicarboxylic acid imide monomer and a vinyl monomer mixture copolymerizable with these, as a second production method, if necessary, in the presence of a bim-like polymer, an aromatic vinyl monomer, an unsaturated A polymer obtained by copolymerizing a dicarboxylic acid anhydride and a vinyl monomer mixture copolymerizable with these is reacted with ammonia and/or 11i & amine to convert 40 to 100 moles of acid anhydride groups into imide groups. The imidized copolymer can be obtained by any of the methods.

The aromatic vinyl monomers used in the first production method of the prison component copolymer include styrene monomers such as styrene, α-methylstyrene, vinyltoluene, t-7” tyrstyrene, chlorostyrene, and substituted styrene monomers. monomers, among which styrene is preferred.

As the unsaturated dicarboxylic acid imir monomer, maleimide,
N-methylmaleimide PXN-butylmaleimide, N-phenylmaleimide, N-methylphenylmaleimide, N
- Maleimide metal conductors such as hydroxyphenylmaleimide, N-methoxyphenylmaleimide, N-chlorophenylmaleimide, N-carboquinphenylmaleimide, N-nitrophenylmaleimide, N-cyclohexylmaleimide, N-isozolobylmaleimide, N- Examples include itaconic acid imide derivatives such as -methyl itaconic acid imide and N-phenyl itaconic acid imide, and among these, N-phenyl maleimide is particularly preferred.

Examples of the unsaturated dicarboxylic anhydride include anhydrides such as maleic acid, itaconic acid, citraconic acid, and aconitic acid, with maleic anhydride being particularly preferred.

Moreover, a vinyl monomer copolymerizable with these may be copolymerized. Copolymerizable vinyl monomers include quinyl cyanide monomers such as acrylonitrile, methacrylonitrile, and α-chloroacrylonitrile, acrylic acid ester monomers such as methyl acrylate and ethyl acrylate, and methyl methacrylate. acid esters, methacrylic acid ester monomers such as ethyl methacrylic acid ester, vinyl carboxylic acid monomers such as acrylic acid and methacrylic acid,
Among these, monomers such as acrylonitrile, methacrylic ester, acrylic acid, and methacrylic acid are preferred.

The temperature of the imivization reaction is about 80 to 650°C, preferably 100 to 300°C. If the temperature is lower than 80°C, the reaction rate is slow and the reaction takes a long time, which is not practical.

On the other hand, if the temperature exceeds 650°C, the physical properties will deteriorate due to thermal decomposition of the polymer.

The amount of acid anhydride residues is adjusted by adjusting the molar equivalent of ammonia and/or primary amine added to the acid anhydride group.

Examples of the solvent for imidization in a solution state include acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, tetrahydrofuran, and dimethylformamide V. Among these, methyl ethyl ketone and methyl isobutyl ketone are preferred. Non-aqueous media for imidization in a turbid state include aliphatic hydrocarbons such as hebutane, hexane, pentane, octane, 2-methylpentane, cyclopentane, and cyclohexane.

Next, the copolymer of the Bl component and its production method will be explained.

(Aromatic vinyl monomers used for the Bl component include styrene, α-methylstyrene, vinyltoluene, t-
Styrene monomers such as f-styrene and chlorostyrene, and substituted monomers thereof, and among these, monomers such as styrene and α-methylstyrene are particularly preferred.

Examples of vinyl cyanide monomers include acrylonitrile, methacrylonitrile, and α-chloroacrylonitrile, with acrylonitrile being particularly preferred. Vinyl monomers that can be copolymerized with these include acrylic ester monomers such as methyl acrylic ester, ethyl acrylic ester, and ethyl acrylic ester, and methacrylic ester monomers such as methyl methacrylic ester and ethyl methacrylic ester. , vinyl carboxylic acid monomers such as acrylic acid and methacrylic acid, acrylamide, and methacrylic acid amide. Among these, methyl methacrylate, acrylic acid, and methacrylic acid are particularly preferred.

(The method for producing the copolymer of the Bl component consists of 40 to 90% by weight of aromatic vinyl monomer residues and 0 to 4% by weight of vinyl cyanide monomer residues.
It is obtained by copolymerizing 1% of 01i and 0 to 40% by weight of vinyl monomer residues copolymerizable with these.

Any known polymerization technique can be employed as the polymerization method, including aqueous heterogeneous polymerization such as suspension polymerization and emulsion polymerization, bulk polymerization, and solution polymerization.

The method of mixing the imide group-containing resin composition of the imidized copolymer (component A) and the copolymer (component B), which are the main components of the present invention, is not particularly limited, and known means can be used. . Examples of such means include a Banbury mixer, a tumbler mixer, a mixing roll, and a single-screw or twin-screw extruder.

As for the mixing form, there are methods of obtaining the composition by ordinary melt mixing, multi-stage melt mixing using a master pellet, etc., and plain r in a solution.

In addition, the imide group-containing resin composition which is the main component of the present invention is
In addition, stabilizers, flame retardants, plasticizers, lubricants, ultraviolet absorbers,
It is also possible to add colorants and fillers such as talc, silica, clay mica, calcium carbonate, etc.

Easily volatile organic liquid blowing agents used in the foaming resin composition of the present invention include hydrocarbon compounds such as propane, butane, pentane, hexane, methylene dichloride, trichloroethylene, dichloroethane, dichlorotetrafluoroethane, trichloroethane, etc. Fluorine compounds such as fluoromethane are mainly used.

The method for producing the encapsulant resin composition of the present invention includes swelling beads or pellets of the imide group-containing resin composition in an autoclave containing a solvent, and heating a readily volatile organic liquid blowing agent. The most common method is to impregnate the resin composition, or to press the resin composition into an extruder and press-in and impregnate it with a readily volatile organic liquid blowing agent while it is in a molten state.
Either combination may be used. The proportion of the easily volatile organic liquid blowing agent impregnated into the foaming resin composition of the present invention is about 2 to 15% by weight of the total amount of the resin composition and the blowing agent. It is 2 to 10% by weight. There is no problem even if the impregnated amount of the liquid blowing agent exceeds 15% by weight, but since the liquid blowing agent evaporates during storage, the economical efficiency decreases. Furthermore, the foaming resin composition of the present invention can be used by manufacturing a resin composition impregnated with a large amount of easily volatile organic liquid blowing agent in advance and diluting it with a non-impregnated resin composition of the same type. There is no problem.

Furthermore, the developing resin composition of the present invention can be used with other resins such as ABS resin, styrene resin, impact-resistant styrene resin,
It can also be used by mixing with polycarbonate resin, nylon resin, PPO resin, modified PPO resin, etc. in a range of 99 to 1% by weight: 1 to 99% by weight. Next, the foam molded product of the present invention is produced by first foaming the retaining resin composition, filling and sealing it in a mold, and heating and foaming it. It can generally be obtained as an extruded foamed product that is extruded into a film or irregular shape, or an injection-molded foamed product that is charged into an injection molding machine, heated and melted, and then injected into a mold.

〔Example〕

The present invention will be explained below with reference to Examples. Incidentally, all parts and parts in the examples are expressed on a weight basis.

(Experimental Example 1) Production of Component A 60 parts of styrene and 50 parts of methyl ethyl ketone were charged into an autoclave equipped with a stirrer, and after purging the system with gold nitrogen gas, the temperature was raised to 85°C, and 40 parts of maleic anhydride and 50 parts of methyl ethyl ketone were charged. A solution of 0.15 parts of benzoyl peroxide dissolved in 250 parts of methyl ethyl ketone was continuously added over 8 hours. The temperature was maintained at 85° C. for an additional 3 hours after the addition. As a result of sampling a part of the viscous reaction liquid and quantifying the polymerization rate by gas chromatography, it was found that styrene was 99%.
, 99% of maleic anhydride. To the copolymer solution obtained here, 0.890 molar equivalents of aniline 34 flFIE,)'J ethylamine 0.0890 molar equivalents to maleic anhydride were added.
3 parts were added and reacted at 140°C for 7 hours.

20 parts of methyl ethyl ketone were added to the reaction solution, cooled to room temperature, stirred vigorously, poured into 1,500 parts of methanol, precipitated, filtered, and dried to obtain an imidized copolymer. C-
According to C-13 part analysis, the maleic anhydride monomer residue is 3.1
% by weight. This was designated as copolymer A-1.

As raw materials for Experimental Example 2, polybutadiene 10 cut into small pieces into 60 parts of styrene and 50 parts of methyl ethyl ketone was used.
An imidized copolymer was obtained by carrying out exactly the same operation as in Experimental Example 1, except that 40 parts and 40 parts of maleic anhydride were charged.

The maleic anhydride monomer residue was 2.8% by weight. This was designated as copolymer A-2.

75 parts of styrene, 25N of acrylonitrile, 2.5 parts of potassium stearate, 0.5 parts of t-p decyl mercaptan
1 part and 250 parts of water were heated to 70°C, and 0.05 part of potassium persulfate was added thereto to initiate polymerization. Seven hours after the start of polymerization, 0.03 part of potassium persulfate was further added, and the temperature was raised to 75°C and maintained for 3 hours to complete polymerization. The polymerization rate reached 97%. The obtained latex was coagulated with calcium chloride, washed with water, and dried to obtain a white powder copolymer. This was designated as copolymer B.

Examples 1 to 4 Copolymer A-7 obtained in Experimental Example 1, Copolymer A-2 obtained in Experimental Example 2, Copolymer B obtained in Experimental Example 6 are shown in Table 1. The mixture was mixed in the following proportions and extruded into pellets using a vented extruder at 2700C to obtain an imide group-containing resin composition.

Next, this pellet 3.0klli+ was
1 Place in an autoclave, add 5.0 kli of pure water, 60011 butane, and 50 g of toluene, then raise the temperature to 120'C (170°C in Example 4) in a trench while stirring, and impregnate at that temperature for 20 hours. I let it happen. Next, after cooling to 30° C., the contents were taken out, washed with water, and dehydrated to obtain retentive resin compositions (C-1 to C-4). The amount of butane impregnated into the resin composition was 5 to 7 inches. In this developing resin composition (C-1 to C-4'lK), no pellets were found to be blocked or locked together.

Next, this attractable resin composition is heated with steam to achieve an actual magnification of 20.
Primary foaming to double the size and after cooling 200X120X2
The mixture was filled into a 0-size mold, heated with steam, and subjected to secondary foaming to obtain a molded product 20 times larger.

The heat resistance of this foamed molded product was measured and the results are shown in Table 1.

/ / / / Beautiful Example 5 A retentive resin composition with a butane impregnation amount of 12% (C
'-5) was obtained. The same operation as in Example 1 was performed to obtain a foamed molded product (expansion ratio: 40 times).

The heat resistance of this foam molded article was also evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 1 Polystyrene resin (Denka Kagaku Kogyo 11 trade name: Denka Styrol MY-1) was used instead of the imide group-containing resin composition used in Example 1, and the impregnation temperature was set to 12
The same procedure as in Example 1 was performed except that the temperature was lowered from 0°C to 80°C to obtain a foamable resin resin with a butane impregnation amount of 6 cm. This foamable resin was foamed in the same manner as in Example 1 to produce a foamed molded product (expansion ratio: 20 times), and evaluated in the same manner as in Example 1.

The results are also listed in Table 1.

Heat resistance in Table: Good: A foamed molded product measuring 200 x 120 x 20 sa++ was heated in the open at 120°C for 5 hours, and after cooling, the degree of expansion or contraction of the molded product was measured.

Good if the foam molded product has expansion or contraction of 2 inches or less on each side: Defective if the foam molded product has expansion or contraction of 2 inches to 10% on each side Bad: 10% of the foam molded product on each side Examples 6 to 10 Examples 1 to 50 The foamable resin was heated to 250 to 200°C, fed to an extruder, extruded through a circular die, and foamed to a thickness of 2W110. Got a sheet.

The sheeting condition and heat resistance of the obtained foam sheet were examined. The results are shown in Table 2.

Comparative Example 2 Comparative Example 1 was used instead of the foamable resin used in Examples 6 to 10.
A styrene resin foam sheet was obtained in the same manner as in Example 6 except for using the foamable polystyrene resin (MY-1) used in Example 6. The physical properties of the obtained foamed sheet were evaluated in the same manner as in Example 6. The results are also listed in Table 2.

Table 1, Heat Resistance: 2[1[1x12Dx2] Foamed sheets were heated in the open at 120°C for 5 hours, and after cooling, the degree of expansion or contraction of the molded product was measured.

Good: Each side of the foam sheet has expanded or contracted within 2% Good: Each side of the foam sheet has expanded or contracted between 2% and 10% Bad: Each side of the foam sheet has expanded or contracted by 10% 2. Sheeting condition 2. The condition of the sheet in the extrusion process of the foamed sheet was visually determined.

Good: There was no surging during extrusion, and the state of bubbles on the sheet surface was almost uniform.

Good: There was no surging during extrusion, and the air bubbles on the sheet surface were almost uniform, but the sheet was brittle enough to not crack when folded.

Poor: The air bubbles on the sheet surface were uneven, the sheet was brittle, and cracks occurred during winding.

Examples 11 to 16 C-1pc of the developing resin composition obtained in Examples 1 to 4
-4 was mixed with other resins in the proportions shown in Table 3, and then fed into an extruder heated at 250 to 2 DOoCK and extruded and foamed through a circular goo to obtain a foam sheet with a thickness of 2 fl. The physical properties of the obtained sheet were evaluated in the same manner as in Example 6. The results are shown in Table 3.

Comparative Examples 4 to 6 The polystyrene resin obtained in Comparative Example 1 was mixed with other resins in the proportions shown in Table 3, then fed to an extruder heated to 250 to 200°C and extruded from a circular die. A foamed sheet having a thickness of 2 mm was obtained by foaming. The physical properties of the obtained sheet were evaluated in the same manner as in Example 6. The result is the 6th
Shown in the table.

／ ／ ／ ／ ／ ／ ／ [Effects of the Invention] As described above, the foaming resin composition of the present invention can be impregnated with a readily volatile organic liquid blowing agent in the same manner as conventional products,
Moreover, the obtained resin composition can be used to freely form foamed molded products from high-foaming molding to low-foaming extrusion molding. Foamed molded products have the characteristics of excellent heat resistance and pressure resistance, and uniform surface bubbles, and are effective in being applicable to a wide range of fields such as packaging materials and building materials.

Claims (1)

[Claims] 1. Component (A): 0 to 40% by weight of rubbery polymer, 30 to 70% by weight of aromatic vinyl monomer residue, 30 to 60% of unsaturated dicarboxylic acid imide monomer residue. (B) 10 to 100% by weight of an imidized copolymer consisting of 1 to 20% by weight of unsaturated dicarboxylic anhydride monomer residues and 0 to 40% by weight of vinyl monomer residues other than these; Component: aromatic vinyl monomer residue 40-90% by weight
, 0 to 40% by weight of vinyl cyanide monomer residues and 90 to 0% by weight of a copolymer consisting of 0 to 40% by weight of vinyl monomer residues copolymerizable with these. A foamable resin composition impregnated with a synthetic organic liquid foaming agent. 2. A foam molded article obtained by foaming the foamable resin composition according to claim 1. 3. A foamable resin composition comprising 99 to 1% by weight of the absorbing resin composition according to claim 1 and 1 to 99% by weight of a resin selected from ABS resin, nylon resin, and polycarbonate resin. 4. A foam molded article obtained by foaming the foamable resin composition according to claim 3.