JP3340223B2 - Synthetic resin composite - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin composite comprising a molded article of a thermoplastic resin composition comprising a specific rubber-containing styrene resin and an acrylic rubber and a urethane foam. More specifically, a rubber-containing styrene-based resin and an acrylic rubber in which the content of an unsaturated nitrile component and the content of an aromatic vinyl component of the rubber-containing styrene-based resin are specified, such as a graft branch, a matrix resin, and a rubber-containing styrene-based resin. And a synthetic resin composite comprising a molded article of a thermoplastic resin composition having improved environmental stress cracking resistance and moldability and a urethane foam, and having heat insulation, vibration damping and sound insulation properties. About.

[0002]

2. Description of the Related Art AB representing rubber-containing styrenic resin
Synthetic resin composites comprising a molded product of S (acrylonitrile-butadiene-styrene) resin and a urethane foam are known, and are widely used, for example, as a heat insulating material in household refrigerators and the like. Such a synthetic resin composite is produced by reacting a mixture mainly composed of a polyisocyanate, a polyol and a foaming agent in the presence of an ABS resin molded article,
Fluorocarbons, ie, CFCs, are widely used as blowing agents.

However, in the synthetic resin composite obtained as described above, the ABS resin molded article may be cracked due to the environmental stress cracking phenomenon. It is thought that the cause is that environmental stress crack fracture occurs when fluorocarbon used as a urethane foaming agent is combined with the tensile stress applied to the ABS resin molded product during the manufacturing process or when a synthetic resin composite is used. .

Meanwhile, it has been pointed out that specific fluorocarbons such as fluorocarbon 11 currently used as a foaming agent have been pointed out as substances causing a greenhouse effect in the global environment or substances causing ozone layer destruction, and production has been suspended from the viewpoint of protecting the global environment. Plans are underway to use alternative CFCs that are less likely to cause environmental damage. However, Freon 123 or Freon 14, which is an alternative Freon to be used as a foaming agent
1b has a greater effect on the environmental stress cracking of the ABS resin than CFC 11, and therefore, a synthetic resin composite manufactured by using CFC 123 or CFC 141b as a foaming agent uses CFC 11. Cracking is more likely to occur in the ABS resin molded product than in the synthetic resin composite.

In order to prevent environmental stress cracking and destruction due to chlorofluorocarbon, the thickness of the ABS resin molded article constituting the synthetic resin composite is increased, or a polyethylene film layer is formed on the interface between the ABS resin molded article and the urethane foam. However, because of poor economical efficiency, development of a synthetic resin composite using an ABS resin molded article having improved environmental stress crack resistance has been desired.

For the purpose of improving the environmental stress cracking property of the synthetic resin composite, the molecular weight of an AS (acrylonitrile-styrene) resin constituting the resin component of the ABS resin to be used is increased, or the polar unit constituting the AS resin is increased. Or increase the composition ratio of acrylonitrile
Methods for copolymerizing a polar monomer other than acrylonitrile with the S resin are known, but these methods involve a reduction in the moldability of the ABS resin, and pose a practical disadvantage when producing an ABS resin molded article. In addition, the effect of improving environmental stress cracking resistance was insufficient.

As a method for improving the environmental stress cracking resistance of a rubber-containing styrene resin such as an ABS resin, the present inventors have already proposed a thermoplastic resin composition comprising a rubber-containing styrene resin and a specific acrylic rubber. (Special Publication 63-22
No. 222, JP-B-63-28445, JP-B-63-28460, JP-B-63-54303, JP-B2-1857, and JP-B-3-52783.
And Japanese Patent Publication No. 3-54984). However, in these inventions, optimization of improvement of environmental stress cracking resistance with respect to alternative CFCs has not been performed. In addition, no means has been proposed to achieve both improvement of environmental stress crack resistance against alternative CFCs and good molding workability, which is inconvenient for practical use as a rubber-containing styrenic resin molded product constituting a synthetic resin composite. was there.

[0008]

As described above, the rubber-containing styrenic resin used in the thermoplastic resin composition constituting the synthetic resin composite has improved environmental stress cracking resistance to alternative chlorofluorocarbons and good molding processing. Improvement of the properties was desired. An object of the present invention is to solve these problems and to provide a synthetic resin composite which is economically superior.

[0009]

DISCLOSURE OF THE INVENTION The present invention comprises a rubber-containing styrenic resin and an acrylic rubber controlled in a specific composition range, has excellent environmental stress cracking resistance to alternative CFCs, and has good moldability. The present invention relates to a synthetic resin composite composed of a molded article of a thermoplastic resin composition having the following and a urethane foam. That is, the present invention provides a synthetic resin comprising a molded article of a thermoplastic resin composition containing 100 parts by weight of a rubber-containing styrene resin having the following characteristics and 0.1 to 100 parts by weight of an acrylic rubber, and a urethane foam. It is a resin composite. The rubber-containing styrene-based resin is composed of (a) 5 to 50% by weight of the graft copolymer [G] and 50 to 95% by weight of the matrix resin [M], and (b) the graft copolymer [G] is conjugated. A copolymer obtained by graft copolymerization of a graft branch [GM] comprising a copolymer of two or more monomers including an unsaturated nitrile monomer and an aromatic vinyl monomer on a diene rubber [B], And the graft branch [GM] is not less than 20% by weight of unsaturated nitrile monomer.
Less than 5% by weight and more than 65% by weight of aromatic vinyl monomer and 8
(C) The matrix resin [M] comprises 35 to 50% by weight of an unsaturated nitrile monomer and 50 to 50% by weight of an aromatic vinyl monomer. (D) the conjugated diene rubber [B] component in the rubber-containing styrene resin is 2 to 40% by weight, and the unsaturated nitrile component is a copolymer of two or more monomers containing 65% by weight. Is 2
It is characterized in that it contains 0 to 50% by weight and the aromatic vinyl component contains 10 to 78% by weight. However,
Rubber rubber except coated acrylic rubber
Good.

The rubber-containing styrenic resin used in the thermoplastic resin composition constituting the synthetic resin composite of the present invention comprises:
It contains a conjugated diene rubber [B], an unsaturated nitrile component and an aromatic vinyl component. The conjugated diene rubber [B] referred to in the present invention refers to a single polymer of a conjugated diene monomer such as butadiene, isoprene and chloroprene. Copolymer or copolymer, unsaturated nitrile component is a polymer of unsaturated nitrile monomer such as acrylonitrile and methacrylonitrile, and aromatic vinyl component is styrene, α-methylstyrene, vinyltoluene, t-butylstyrene, The polymer is a polymer of an aromatic vinyl monomer such as bromostyrene.

The rubber-containing styrene resin used in the present invention comprises a graft copolymer [G] and a matrix resin [M], and the graft copolymer [G] is graft-bonded to a conjugated diene rubber [B]. [GM] is graft copolymerized, the graft branch [GM] is a copolymer containing an unsaturated nitrile monomer and an aromatic vinyl monomer, and the matrix resin [M] is different from the graft branch [GM]. A copolymer containing an unsaturated nitrile monomer having a composition and an aromatic vinyl monomer.

The rubber-containing styrene resin used in the present invention comprises a graft copolymer [G] constituting a dispersed phase and a matrix resin [M] constituting a continuous phase. In general, a method in which the required amount of an unsaturated nitrile monomer and an aromatic vinyl monomer is added to the presence of a conjugated diene rubber [B] latex produced by emulsion polymerization to carry out emulsion radical polymerization is generally used industrially. Will be It is also known to add a separately produced matrix resin to the rubber-containing styrene resin obtained by such a production method. In the present invention, the rubber-containing styrenic resin can be produced by such a method, but the production method is not particularly limited.

[0013] Rubber-containing styrene resins used industrially are conjugated diene rubbers [B] and graft branches [GM] for the purpose of improving properties such as rigidity, heat resistance, impact resistance and moldability. Alternatively, during the production of the matrix resin [M], it is common practice to add a monomer other than the above-mentioned monomer to the above-mentioned monomer constituting the polymer and copolymerize it. However, such monomers include, for example, (meth) acrylic acid, methyl (meth) acrylate,
Ethyl (meth) acrylates such as ethyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, stearyl (meth) acrylate, and cyclohexyl (meth) acrylate Monomers, maleimide monomers such as maleimide, N-butylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, (meth) acrylamide, maleic anhydride and the like.

The rubber-containing styrenic resin used in the present invention comprises: (a) 5 to 50% by weight of a graft copolymer [G] and 50 to 95% by weight of a matrix resin [M]; The graft [G] is obtained by graft copolymerization of a graft branch [GM] consisting of a copolymer of two or more monomers including an unsaturated nitrile monomer and an aromatic vinyl monomer on a conjugated diene rubber [B]. And the graft branch [GM] is not less than 20% by weight of the unsaturated nitrile monomer.
Less than 5% by weight and more than 65% by weight of aromatic vinyl monomer and 8
0 is a copolymer of two or more monomers comprising by weight percent, (c) the matrix resin [M] is 50 to unsaturated nitrile monomer 35 to 50 wt% and an aromatic vinyl monomer (D) the conjugated diene rubber [B] component in the rubber-containing styrene resin is 2 to 40% by weight, and the unsaturated nitrile component is a copolymer of two or more monomers containing 65% by weight. Is 2
It is characterized in that it contains 0 to 50% by weight and the aromatic vinyl component contains 10 to 78% by weight. These constituents are conditions for the synthetic resin composite of the present invention to have practically preferable environmental stress crack resistance and moldability.

In order to improve the environmental stress cracking resistance of rubber-containing styrenic resin against CFC substitute, an unsaturated nitrile component constituting the rubber-containing styrenic resin is disclosed in, for example, JP-A-5-155949. May be increased, but as the composition ratio of the unsaturated nitrile component increases, the melt viscosity of the resin increases, resulting in an industrially unfavorable decrease in molding processability. However, according to the findings of the present inventors, when increasing the composition ratio of the unsaturated nitrile component constituting the rubber-containing styrenic resin,
By suppressing the unsaturated nitrile component of the graft branch [GM] low and increasing the unsaturated nitrile component of the matrix resin [M], a thermoplastic resin composition having high resistance to environmental stress cracking and good moldability can be obtained. Obtained and used suitably for a synthetic resin composite. That is, the rubber-containing styrenic resin used in the present invention is inferior in environmental stress cracking resistance when the unsaturated nitrile component is less than 20% by weight, and inferior in moldability when it exceeds 50% by weight. When the amount of the unsaturated nitrile monomer of the graft branch [GM] constituting the graft copolymer [G] of the rubber-containing styrene resin used in the present invention exceeds 35% by weight, the moldability is poor. If the amount of the unsaturated nitrile monomer in the matrix resin [M] is less than 35% by weight, the resistance to environmental stress cracking is poor, and if it exceeds 50% by weight, the moldability is poor.

In order to produce a rubber-containing styrene resin having different compositions of the graft branch [GM] and the matrix resin [M], an unsaturated nitrile monomer polymerized in the presence of a diene rubber [B] and an aromatic monomer are used. There are a method of sequentially changing the composition ratio of the genus vinyl monomer, a method of mixing a matrix resin having a different composition with the rubber-containing styrene-based resin, and the like, but the production method is not limited.

The acrylic rubber used in the thermoplastic resin composition constituting the synthetic resin composite of the present invention is a homo- or copolymer of a (meth) acrylic ester-based monomer. Is the unsaturated nitrile monomer described above,
In addition to aromatic vinyl monomers, maleimide monomers, (meth) acrylamide and maleic anhydride, olefin monomers such as ethylene, propylene, 1-butene, isobutylene and 2-butene, and fatty acid vinyls such as vinyl acetate There are monomers and the like.

It is known to use graft-polymerized acrylic rubber for the purpose of improving the compatibility between the acrylic rubber and the rubber-containing styrenic resin (Japanese Patent Publication No. Sho 63-2).
8445, JP-B-63-28460),
The acrylic rubber used in the present invention may be an acrylic rubber having a graft branch disclosed in the publication. In the present invention, as the acrylic rubber,
Excludes coated acrylic rubber.

The acrylic rubber used in the present invention preferably has a glass transition temperature of 20 ° C. or less. When the glass transition temperature exceeds 20 ° C., the environmental stress cracking resistance of the thermoplastic resin composition is insufficient. In the case where the acrylic rubber has a graft branch, the glass transition temperature of the acrylic rubber refers to the glass transition temperature of the trunk polymer containing no graft branch.

The thermoplastic resin composition used in the present invention can be obtained by containing a rubber-containing styrenic resin and an acrylic rubber, but the production method is arbitrary. For example, when both a rubber-containing styrene resin and an acrylic rubber are produced by emulsion polymerization, the resulting polymer latex can be mixed according to the method described in JP-B-63-22222. The acrylic rubber composition premixed in an emulsified state according to the method described in Japanese Patent Publication No. 3-52783 can be separately melt-kneaded with a rubber-containing styrene resin. Further, a method of mixing an acrylic rubber latex with a rubber-containing styrene resin solid using the method disclosed in Japanese Patent Publication No. 59-15942 is also possible. When both the rubber-containing styrene resin and the acrylic rubber are solid, they can be melt-mixed by a melt-mixing device such as a screw extruder or a Banbury mixer.

The thermoplastic resin composition used in the present invention comprises 100 parts by weight of a rubber-containing styrene resin and 0.1 part of acrylic rubber.
When the content of the acrylic rubber is less than 0.1 part by weight, the resulting thermoplastic resin composition has insufficient environmental stress cracking resistance, and when the content exceeds 100 parts by weight. Not only does the effect saturate, but also the properties of the thermoplastic resin composition such as heat resistance, rigidity, gloss and the like are undesirably reduced. When the acrylic rubber has a graft branch, the content of the acrylic rubber refers to the content of the trunk polymer not containing the graft branch.

The thermoplastic resin composition used in the present invention can be mixed with other polymer materials for the purpose of improving properties such as impact resistance, heat resistance, rigidity and flame retardancy. Such polymer materials include SBR (styrene-butadiene rubber), EPR (ethylene-propylene rubber), NBR
Elastomers such as (acrylonitrile-butadiene rubber); polyolefins such as polyethylene and polypropylene; polyamides such as nylon 6, nylon 66, nylon 610, nylon 612, nylon 11, and nylon 12; polyesters such as polyethylene terephthalate and polybutylene terephthalate; There are acrylic resin and polyvinyl chloride.

The synthetic resin composite of the present invention is produced by reacting a mixture mainly composed of a polyisocyanate, a polyol and a foaming agent in the presence of a molded thermoplastic resin composition which has been molded beforehand. The composition and production method of the urethane foam of the present invention are not particularly limited.

Specific examples of the polyisocyanate used for producing the urethane foam include tolylene diisocyanate, o
-Tolidine diisocyanate, diphenylmethane-4,
4'-diisocyanate, 1,3-xylylene diisocyanate, naphthylene-1,5-diisocyanate, 1
-Methylcyclohexane-2,4-diisocyanate. Specific examples of the polyol are 1,4-butanediol, ethylene glycol, polyethylene glycol,
Propylene glycol, polypropylene glycol, poly (ethylene oxide-propylene oxide) copolymer, α, ω-polycaprolactone diol, α, ω-
Diols such as polybutadiene diol, glycerin,
Examples include triols such as trimethylolpropane, pentaerythritol, methylglycoside, sorbitol, and soucrose, and adducts of ethylene oxide or propylene oxide with these polyols. Examples of the foaming agent include Freon 11, Freon 12, Freon 113, Freon 123, Freon 141b, and methylene chloride.

In the production of urethane foams, it is known to use water acting as a chemical foaming agent, an organotin compound, a catalyst represented by a tertiary amine, a surfactant acting as a foam stabilizer, and the like. Although a number of techniques have been disclosed for these methods of use, there is no particular limitation on the urethane foam formulation in the present invention.

[0026]

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. The parts and percentages in the examples are shown on a weight basis.

The abbreviations used in the examples and comparative examples are as follows. PB: polybutadiene SBR: styrene-butadiene rubber AN: acrylonitrile SM: styrene nBA: n-butyl acrylate MMA: methyl methacrylate AMA: allyl methacrylate

Examples and Comparative Examples The ABS resin shown in Table 1, the AS resin shown in Table 2, and the acrylic rubber shown in Tables 3 and 4 were used in Table 5 (A constituting the thermoplastic resin composition).
BS resin characteristics), blended according to the formulations described in Tables 6 and 7 (composition of thermoplastic resin composition and properties of synthetic resin composite), and melt-kneaded at about 240 ° C to obtain a thermoplastic resin composition. Was.

5 parts of a titanium oxide pigment was mixed with the obtained thermoplastic resin composition, supplied to a single screw extruder equipped with a T-die, melted at about 220 ° C., and processed into a flat plate having an average thickness of 1 mm. . The obtained flat plate is pre-dried and formed by a plug-assist type air-pressure vacuum forming machine while controlling the surface temperature of the flat plate to about 160 ° C. to form a coverless box-shaped heat-resistant box having a matte pattern on the bottom shown in FIG. A molded article of the plastic resin composition was obtained. This molded article is combined with the open box-shaped steel molded article shown in FIG. 1, and in a space surrounded by both molded articles, 110 parts of tolylene diisocyanate, an adduct of methyl glycoside and propylene oxide (hydroxyl equivalent 110) 100 parts, Freon 14
A mixture consisting of 30 parts of 1b, 3.5 parts of water, 0.4 parts of di-n-octyltin laurate and 0.2 parts of tetramethylguanidine was injected, and reacted at 50 ° C. for 30 minutes to obtain a synthetic resin composite. Was. The dimensions of the synthetic resin composite of FIG. 1 are 175 mm in width × 256 mm in length × 30 mm in height, and the thickness of the urethane foam is 5 mm.

Examples are shown in Experiment Nos. 1 to 15 in Tables 6 and 7, and Comparative Examples are shown in Experiment Nos. 16 to 21 in Table 7. As is clear from Tables 6 and 7, the thermoplastic resin composition constituting the synthetic resin composite of the present invention has good industrially favorable moldability and, moreover, a molded article of the thermoplastic resin composition. Is excellent in environmental stress crack resistance to CFC 141b.

The production of the ABS resin, acrylic rubber and thermoplastic resin composition described in Examples and Comparative Examples was carried out as follows. (1) ABS resin production method Polybutadiene latex or polybutadiene latex and styrene-butadiene rubber (styrene content 2
5%) Ion-exchanged water, an emulsifier, and a reducing agent containing ferrous sulfate are added to a stainless steel reactor charged with a mixture of latex, and acrylonitrile, styrene, and cumenehydro are maintained under a nitrogen atmosphere while maintaining the temperature at 50 ° C. Emulsion graft polymerization was carried out by continuously lowering a mixture of peroxide and n-dodecyl mercaptan for 5 hours. After completion of the lowering, the temperature was raised to 70 ° C. and maintained for another 2 hours to complete the polymerization. The characteristics of the obtained ABS resin are shown in Table 1.

(2) Acrylic Rubber Production Method A stainless steel reactor was charged with ion-exchanged water, an emulsifier, and potassium sulfate, and the temperature was maintained at 70 ° C. under a nitrogen atmosphere, and the (meth) acrylic acid shown in Table 3 was obtained. Emulsion polymerization was carried out by continuously lowering the ester monomer mixture for 7 hours, and further kept at 70 ° C. for 2 hours to complete the polymerization to obtain an acrylic rubber. Table 3 shows the characteristics of the obtained acrylic rubber.

(3) Graft Polymerization of AN and SM onto Acrylic Rubber A stainless steel reactor charged with acrylic rubber latex of sample number c1, c3 or c4 in Table 3 contains a reducing agent containing ion-exchanged water and ferrous sulfate. Was added and the temperature was maintained at 50 ° C. under a nitrogen atmosphere. Emulsion graft polymerization was performed by continuously lowering a mixture of acrylonitrile, styrene, n-dodecyl mercaptan, and cumene hydroperoxide and an aqueous emulsifier solution. After completion of the lowering, the temperature was raised to 70 ° C. and maintained for 2 hours to complete the polymerization. Table 4 summarizes the characteristics of the obtained graft polymer.

(4) Preparation of thermoplastic resin composition The ABS resin latex shown in Table 1 and the acrylic rubber latex shown in Table 3 or Table 4 were mixed in a latex state, and a suspension of an antioxidant was added. Dilute sulfuric acid was poured at about 90 ° C. to precipitate a latex. The obtained slurry was dehydrated and dried to obtain a polymer powder. The obtained polymer powder and the AS resin powder shown in Table 2 were mixed with a Henschel mixer and melt-kneaded at about 240 ° C. using a twin-screw extruder to obtain a heat having the compositions shown in Tables 6 and 7. A plastic resin composition was obtained. The ABS resin constituting the thermoplastic resin compositions in Tables 6 and 7 is a mixture of the ABS resin in Table 1 and the AS resin in Table 2, and has the composition described in Table 5.

The obtained synthetic resin composite was evaluated as follows. (1) Moldability The following evaluation was performed by observing the appearance of the molded article in FIG. A: The pattern on the bottom is clearly transferred, and the ridges and corners of the box are also acute. B: The pattern on the bottom is slightly unclear, and the edges and corners of the box are also slightly obtuse. C: The pattern on the bottom is extremely unclear, and the ridges and corners of the box are obtuse.

(2) Environmental Stress Cracking Resistance The synthetic resin composite was placed in a thermostat, and a cooling / heating cycle of −30 ° C./12 hours to 40 ° C./12 hours was repeated three times.
The molded article of the thermoplastic resin composition was removed from the synthetic resin composite after the thermal cycle test, and the appearance was observed. A: No change B: Partial whitening is observed C: Cracking occurs

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

[Table 3]

[0040]

[Table 4]

[0041]

[Table 5]

[0042]

[Table 6]

[0043]

[Table 7]

[0044]

As described above, in the synthetic resin composite of the present invention, the moldability of the thermoplastic resin composition is good, and the obtained synthetic resin composite has environmental stress crack resistance. It is suitable for applications such as heat insulating materials, vibration damping materials, and sound insulating materials.

[Brief description of the drawings]

FIG. 1A is a sectional view of an ABS resin molded product.
(B) shows a top view of the synthetic resin composite. (C) is a cross-sectional view of AA ′ of the synthetic resin composite of (b).

[Explanation of symbols]

 1: ABS resin molded body 2: steel molded body 3: urethane foam

Continuation of front page (56) References JP-A-7-96573 (JP, A) JP-A-7-33900 (JP, A) JP-A-7-48466 (JP, A) JP-A-5-339450 (JP) JP-A-5-320462 (JP, A) JP-A-4-170460 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35/00 F25D 23/00-23/12 C08L 55/02

Claims (3)

(57) [Claims] 1. A synthetic composition comprising a molded article of a thermoplastic resin composition containing 100 parts by weight of a rubber-containing styrene resin having the following characteristics and 0.1 to 100 parts by weight of an acrylic rubber, and a urethane foam. Resin composite. The rubber-containing styrene resin comprises (a) 5 to 50% by weight of a graft copolymer [G] and 50 to 95% by weight of a matrix resin [M], and (b) the graft copolymer [G] is a conjugated diene. A copolymer obtained by graft-copolymerizing a graft branch [GM] comprising a copolymer of two or more types of monomers including an unsaturated nitrile monomer and an aromatic vinyl monomer on a base rubber [B], and The graft branch [GM] is not less than 20% by weight of the unsaturated nitrile monomer.
Less than 5% by weight and more than 65% by weight of aromatic vinyl monomer and 8
(C) The matrix resin [M] is composed of 35 to 50% by weight of an unsaturated nitrile monomer and 50 to 50% by weight of an aromatic vinyl monomer. (D) the conjugated diene rubber [B] component in the rubber-containing styrene resin is 2 to 40% by weight, and the unsaturated nitrile component is a copolymer of two or more monomers containing 65% by weight. Is 2
0 to 50% by weight and the aromatic vinyl component comprise 10 to 78% by weight. However, acrylic rubber is coated
Excluded acrylic rubber. 2. The synthetic resin composite according to claim 1, wherein the rubber-containing styrenic resin is an ABS resin. 3. The glass transition temperature of the acrylic rubber is 20 ° C.
The synthetic resin composite according to claim 1, wherein However, acrylic
Rubber excludes coated acrylic rubber.