JPS60147330A - Composite heat-insulating material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite heat insulating material used as a lining material for the body and door of a refrigerator. The composite heat insulating material of the present invention is a heat insulating material having a structure in which urethane foam and a sheet of polyolefin resin or styrene resin are firmly adhered.

The main body and door of the refrigerator are made of baked-on stainless steel or steel plate, and are made of acrylonitrile, a styrene resin, and butadiene-styrene copolymer (commonly known as rABsJ) to protect the structural base material (outer frame) of steel plates and form shelves. 1. Vacuum forming or pressure forming of sheets is also possible. < is equipped with a lining material obtained by molding using a combination of vacuum and compressed air (hereinafter, these molding methods are collectively referred to as differential pressure molding). In addition, attempts have also been made to use polypropylene lining materials, which have excellent surface gloss and low water absorption, instead of internally made ABS lining materials.

In order to improve the heat insulation properties of refrigerators, it has been proposed to interpose urethane foam between the baking-painted stainless steel plate, which is the structural base material of the refrigerator, and the lining material, but it is difficult to obtain such a laminated structure. When an olefin resin sheet is used as the lining and exterior material, it is necessary to strengthen the adhesion between the polyolefin resin sheet and the urethane foam, which is a heat insulating material. For this purpose, the interior and exterior materials, which have been differential pressure molded in advance, and the urethane foam are laminated using liquid acrylic adhesive or epoxy adhesive, and then this laminated material is baked with adhesive applied to the inside. This is done by inserting and crimping the coated stainless steel into a structural base material (formwork), but a method that involves multiple steps would be expensive. Therefore, as shown in Figure 1, a foamable urethane solution (4) is injected into the cavity (3) formed by the mold (1) and the lining material (2), and then foamed and cured. It is preferable to use an on-site construction method in which a multilayer structure is manufactured in which the formwork (1), the urethane foam (4'), and the lining material (2) are integrated.

Furthermore, it is conceivable to apply an organic solvent-based adhesive to the polyolefin resin sheet in advance, allow it to dry, and then bond it to the urethane foam, which is an insulating material. The working environment is not favorable.

Furthermore, before differential pressure molding is performed on an ABS or polyolefin sheet, it is necessary to wipe off dust adhering to the surface of the sheet with a cloth or the like. This problem can be solved by kneading an antistatic agent into the resin of the sheet material and using a sheet made of this. After forming the sheet, the sheet must be heated 30 to 50 times before the prevention function is imparted.
The antistatic function cannot be imparted to the sheet unless it is stored for several days. On the other hand, it is necessary to take care to ensure that the sheet storage period is not affected by dust, but this is not a good idea. The present invention was achieved after various studies were conducted on a coating type adhesive composition that satisfies such fold-requiring performance when manufactured by a construction method.

That is, the present invention provides a composite heat insulating material having a structure in which a polyolefin resin or a styrene resin and a urethane foam are laminated with an adhesive containing the following components (1) and (2).Adhesive composition: ω, water-soluble or water-dispersible carboxyl group-containing polyolefin polymer.

20-100% by weight (6), 0-100% of other water-soluble polymers with antistatic properties
80% by weight.

In the present invention, the resin for the sheet material includes high-density polyethylene, low-density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene copolymer,
Polyolefin resins with butene copolymer status: polyethylene, styrene/phtadiene/styrene block copolymer (so-called 5BS), acrylonitrile/butadiene/styrene block copolymer (so-called 5BS),
Examples include styrene resins such as styrene copolymers (so-called ABS) and high-impact dilystyrene (so-called HIPS). These may be used alone or in combination of two or more. A stabilizer, an inorganic filler, a pigment, a rubber, etc. may be added to this resin. These resins are extruded into a sheet, and if necessary, the front and/or back surfaces are subjected to corona discharge treatment to form a differential pressure molding sheet with a wall thickness of 0.3 to 4 cm.

Next, as an adhesive composition, the above-mentioned component (1) may be used alone, or the component (2) may be contained in an amount of 20% by weight (solid content) or more.
Mixtures containing components in proportions of up to 80% by weight are used, and the adhesive is used as an aqueous solution or dispersion with a concentration of 0.5 to 3% by weight, preferably with an ω component of 20 to 30% by weight.
An adhesive consisting of a mixture of 80% by weight and 80 to 20% component (1) is preferred from the viewpoint of antistatic properties. however,(
4) The content of the carboxyl group-containing polyolefin polymer is 85% to 100% by weight! ! -%, the antistatic function until the resin sheet is thermoformed cannot be said to be sufficient. and (13) a mixture of 100 to 20% by weight, or anionic surfactant, cationic surfactant, amphoteric surfactant, nonionic surfactant, such as lauryl aminopropionate sodium salt, stearyl trimethyl Ammonium chloride, 1-hydroxyethyl-2-undecyl-
It is necessary to apply an antistatic agent such as 2-imidacillin/ethylene oxide adduct, nonylphenol/ethylene oxide adduct, or lauryl sulfate/sodium salt.

As the water-soluble or water-dispersible carboxyl group-containing polyolefin polymer of the component By copolymerizing with an olefin such as ethylene, or by graft copolymerizing the carboxylic acid onto a polyolefin, or by randomly copolymerizing an unsaturated carboxylic acid ester such as an alkyl (meth)acrylic acid ester with ethylene, or a polyolefin. Graft copolymerized with
It can then be obtained by saponification. Furthermore, in order to water-solubilize or water-disperse this carboxyl-containing polyolefin, it is necessary to add an alkaline aqueous solution such as ammonia or back soda to the carboxyl-containing polyolefin to make it water-solubilized or self-emulsify it, or to use other emulsifiers, protective colloids, etc. It can be produced by a known method of water dispersion using. It is sufficient if it is on the carboxyl group-containing Borioles. This carboxyl group-containing polyolefin polymer, component (1), greatly contributes to the adhesive property with urethane.

Q3) The water-soluble polymer that has antistatic properties as an ingredient may be cationic, anionic, nonionic, or amphoteric, and is not particularly limited. It is good if it is selected.

Specifically, the component (1) includes polyethyleneimine, poly(ethyleneimine-urea), ethyleneimine adducts of polyamine polyamides, and nitrogen atom-containing cationic or amphoteric polymers.

This nitrogen-containing water-soluble polymer can be obtained by homopolymerizing nitrogen-containing monomers or by copolymerizing these monomers with other copolymerizable monomers.

Specific examples of nitrogen-containing monomers include the following.

(a) 1 ong-N to) ni)′ Ua (to) (to)・ (a) Solution Here, in each formula, R1 is hydrogen or a methyl group, and R2 and R8 are each a lower alkyl group (especially, cl ~C4,
Among them, C1-C2), R4 is a saturated or unsaturated alkyl group having 1 to 22 carbon atoms or a benzyl group, door is a quaternized - counter anion (for example, halide (especially chloride)), and A is a carbon number 2 to 6 alkylene groups.

The nitrogen-containing water-soluble polymer of component (B) is composed of these four ψ (amphoterized) nine element-containing monomers ←), ni), υ, (he), kō, (
It can be obtained by homopolymerizing a), moe, and (g), or by copolymerizing these quaternary nitrogen-containing monomers with other vinyl monomers. In addition, tertiary nitrogen-containing monomers (a), (
C), (E), and (A) are homopolymerized or copolymerized with other monomers, and then alkyl halide, dimethyl sulfate,
It can be quaternized with a cationizing agent such as benzyl halide monochloroacetic acid ester, or amphotericized with an amphoteric agent such as monochloroacetic acid (salt), panthanstone, or violactone, so that it can be present in the polymer. Needless to say, it is possible to do K.

In the present invention, the polymer component (8) needs to be water-soluble, but it is not desirable that it be excessively water-soluble. Therefore, this tertiary to quaternary nitrogen-containing polymer is preferably a copolymer with a hydrophobic monomer. Examples of the hydrophobic monomer include styrene or its substituted derivatives in the nucleus or side chain, acrylic or methacrylic acid esters, vinyl halides, and others.

Particularly suitable nitrogen-containing water-soluble polymers in the present invention are as follows (a
) to (C) are copolymerized acrylic polymers.

(a) Monomer 0) to (to) 20 to 40% by weight 1 佽)C几=C-C0OR' 6 to 80 weight-[In the formula, R
1 is H or a methyl group, or an alkyl group of R'ti Ct to Crs] (c) Other hydrophobic vinyl monomers 0 to 20% by weight.

The most suitable acrylic polymer as component (i) in the present invention is (a
) The monomer is the above-mentioned monomer (e) and the value is c/e.

This acrylic polymer is 5 from Mitsubishi Yuka Fine ■.
T-1000% i9'l'-1100% 5T-13
It is sold under the trade name 00.5T-3000.

An aqueous solution (2a, 2e) of an adhesive having an antistatic function containing these components and CB) is applied by means such as rolling, brushing, spraying, etc. to at least the back side of the adhesive (2b) that will be bonded to the urethane. , 0.01.~1. Of/rr
? (Solid content) is coated and dried (see Figure 2).

The antistatic resin film (2a) thus obtained.

The resin sheet having 2c) on the front and back surfaces or with a back side pressure bonded to urethane is subjected to normal differential pressure molding and shaped into a shape suitable for a refrigerator lining material.

This shaped sheet (2) is perforated with an injection port (5) for the urethane solution (4) as required, and as shown in Figure 1, the sheet is made of stainless steel and made of aluminum, which is the outer structural base material of the refrigerator. It is inserted into the forming frame (1). Next, for example, a two-part foaming urethane solution is added to the mold (1
) and the lining material (2) are injected into the cavity (4) formed by urethane foam molding, and the urethane foam bacteria and the lining material (2) are firmly bonded together to form a multi-layered structure with heat insulating properties. A lining material is formed.

Hereinafter, the present invention will be explained in more detail with reference to Examples. Note that parts and parts in the examples are based on weight.

Sheet manufacturing example Example 1 (1) Resin used for glossy layer: MF temperature, or/lo minute,
A crystalline propylene homopolymer with a residual amount of 99% by weight after extraction with boiling hebutane was used.

(i>Resin for deep drawing layer: ethylene content 5% by weight,
MFRo, 5 f/10 min, boiling hebutane extraction remaining 98
40% by weight of crystalline propylene-ethylene block copolymer and a density of 0.9 soy/aR.

MFRo, 6 r/10 min polyethylene 40% by weight,
A composition consisting of 20% by weight of talc with a particle size of 1.5 μm was kneaded with an extruder, extruded into a strand, and cut into pellets.

The resin pellets for the deep drawing layer in (g) above were fed to a two-layer multi-manifold die with a width of 700 m at 230°C using an extruder with a diameter of 90 mm, and the resin for the glossy layer in trench (1) was fed into a 2-layer multi-manifold die with a diameter of 40 m. The extruder was used to feed the same die at 230 mm.

The die temperature was 230°C. The molten sheet extruded from the die was sequentially cooled and solidified using three rolls each having a width of 700 mm, and then subjected to corona discharge treatment to obtain a sheet for vacuum forming. The temperature of the rolls is 80℃ starting from the roll closest to the die.
The temperatures are 95°C and 100°C, and the rotation speed of the roll is 1.
The speed was 5 m/min. The total sheet thickness was 1.6 mm, the gloss layer was 0.25 mm, and the deep drawing layer was 1.35 mm thick.

Example 2 Polypropylene manufactured by Mitsubishi Yuka ■ 1 Mitsubishi Noblen MA-8
' (trade name) was extruded into a sheet at 230°C, and then subjected to corona discharge treatment to obtain a sheet with a wall thickness of 1.6 strips.

Example 3 ABS resin 1 Tuflex 15 manufactured by Mitsubishi Monsanto Kasei ■
7" (trade name) was extruded into a sheet at 220°C to obtain a sheet with a wall thickness of 1.6 tm.

Example 4 Polypropylene 1 Mitsubishi Noiprene ME (-6135 parts High density polyethylene 1 Yucalon Hard EY-40" 2
5 parts styrene-butadiene-styrene copolymer 12 parts talc 24 parts titanium oxide 4 parts The above resin composition was used in place of polypropylene, and the other conditions were the same as in Example 2 to obtain a sheet with a thickness of 1.6.

Example 5 (1) Resin used for the glossy layer: A crystalline propylene homopolymer with an MFR of 2, Of/10 minutes and a residual amount of 99% by weight after extraction with boiling hebutane was used.

(4) Resin for deep drawing layer: 1 part polypropylene 1 part Mitsubishi Noprene MH-6''' 25 parts High-density polyethylene 1 part Yucalon Hard EV-40' 1 part
5 parts styrene-butadiene-styrene copolymer 12
Part calcium carbonate 40 parts Polystyrene 8 parts The resin required for deep drawing (-) above was supplied to a three-layer multi-manifold die with a width of 700 mm at 230°C using an extruder with a diameter of 9 (1 m), and the gloss of (1) Layer resin with diameter 40
- were fed into the same die at 230°C using an extruder. The die temperature Jd was 230°C. The molten sheet extruded from the die was sequentially cooled and solidified using three rolls with a width of 700 m, and then subjected to corona discharge treatment to obtain a sheet for vacuum forming. The temperature of the rolls is 80℃ from the roll closest to the die, 9
5℃, 100℃, and the rotation speed of the roll is 1.5
m/min. The total sheet thickness was 1.6 mm, the glossy layers on the front and back sides were each 0.2 mm, and the deep drawing layer in the middle was 1.2 mm.

Production example of acrylic polymer (color) component N, part of N-dimethylaminoethyl methacrylate so (0.5 mol), 50 parts of methyl methacrylate (0, s mol) and 200 parts of Improvil alcohol were mixed in a stirrer and a reflux condenser. , a thermometer, and a dropping funnel, and after purging with nitrogen gas, 0.9 part of 2,2'-azobisisobutyronitrile was added as a polymerization initiator, and the mixture was heated at 80°C for 4 hours. A polymerization reaction was performed.

Next, 60 parts of monochlorosodium acetate was added and the reaction was carried out at 80°C for 6 hours (amphoterization), and then water was added while distilling off the inglobil alcohol to obtain an aqueous solution with a solid content of 35 g. .

This acrylic polymer (hereinafter referred to as -8TJ) contains a droplet in its molecular chain.

Example 1 50% of the acrylic polymer obtained in the above example and carboxyl group-containing polyolefin aqueous emulsion "Zaikusen AC" (trade name) 50% of Seitetsu Kagaku Kogyo ■ were applied on both sides of the two-layered sheet obtained in Example 1 above. An aqueous dispersion of a mixed polymer with a solid content ratio of
? (solid content) and allowed to air dry.

The surface specific resistance value of this sheet is 2. It was OX 10”Ω・tan.

This sheet was introduced into a heating furnace set at about 220° C. using a vacuum/pressure forming machine, and plug-assisted molding was performed using a combination of compressed air (5, OK9/d) and reduced pressure (-600") Tg).

After drilling an injection port in a part of this shaped sheet, this sheet is inserted into a stainless steel frame that is the frame of the refrigerator body, and then the space formed by the frame and the shaped sheet is Inject the two-component foaming urethane solution "KM-1510" manufactured by Polyurethane Kagaku Kasei@ into the injection port.
When 1 (trade name) was injected, foaming started after 10 seconds, and the space in the diameter was completely filled with ``F'-KxF''.
Satisfied. The density of this urethane foam is 0.05f
/crl.

After 24 hours, the sheet to which the urethane foam had been adhered was cut out, and the adhesion between the urethane 7 ohm and the sheet was measured. On the other hand, another sheet (not bonded with urethane) that had been vacuum formed in the same manner as the above sheet was partially cut out, and the specific resistance value and ash adhesion of the sheet surface were examined. The results are shown below.

Surface specific resistance value*: 2.5 x 10”Ω・Tsubaki ash adhesion:
No adhesion 1/Adhesion between tongue and sheet: Good (○) Anti-blocking property **: Good (0) *Measurement at 20°C and 60° relative humidity Examples 2 to 8, Comparative Examples 1 to 2 The above implementation A urethane foam/sheet laminated heat insulating material was obtained in the same manner as in Example 1 except that the coating agent was changed as shown in Table 1.

This laminated heat insulating material was evaluated in the same manner as in Example 1.

The results are shown in Table 1.

The evaluation criteria are as follows. Ash adhesion: Adheres even at heights higher than X-5511 Adheres at a height of Δ-3 to 5erII Adheres or does not adhere below 0-3cIII.

Adhesion between urethane and sheet: XX = The sheet and urethane foam peel off without resistance.

There is some resistance to cutting, and the urethane foam peels off from the sheet interface.

Δ-The urethane foam peels off from the base material in some parts.

〇-The entire urethane foam base material peels off.

(Left space below) Examples 9 to 13 Urethane foam was formed in the same manner as in Example 1, except that the sheets obtained in Examples 2 to 5 were used instead of the laminated sheet obtained in Example 1 as the sheet for differential pressure molding. /Sheet laminated insulation material was obtained.

The physical properties of this product are shown in Table 2.

(Margin below)

[Brief explanation of drawings]

1st r! ? I is a sectional view showing one embodiment of the present invention, and FIG. 2 is a sectional view of the sheet. In the figure, 1 is a stainless steel frame, 2 is a differential pressure molding sheet (
lining material), 2a and 2C are coating agent layers, 3tt cavity,
4' is a urethane foam, and 5 is an injection port. Patent Applicant Mitsubishi Yuka Co., Ltd. Agent Patent Attorney Hidetoshi Furukawa Agent Patent Attorney Masahisa Hase Continuation of page 1 ■Int, C1,' Identification code Office reference number 0 Inventor Isao Ito Yokkaichi City Inside Tohocho 1st Research Institute ■Inventor Yukio Saito Inside Tohocho 1st Research Institute, Yokkaichi City

Claims (1)

[Claims] 1) a polyolefin resin or a styrene resin;
Adhesive composition for a composite heat insulating material in which urethane foam is laminated with an adhesive containing the following ω component and CB) component: (4) Water-soluble or water-dispersible carboxyl group-containing polyolefin polymer 20 to 100% by weight % Q3), other water-soluble polymers with antistatic performance 0~
80% by weight 2) The @ component is an amphoteric compound obtained by modifying the tertiary nitrogen atom of a polymer consisting of the following components (a) to (c) with an amphoteric agent. Composite insulation material 1 (c) Other hydrophobic vinyl monomers 0 to 20% by weight (Tata L, in each formula, R" H-1 Rike CI (a, R2 and R
8 is H or an alkyl group having 1 to 2 carbon atoms R5
is an alkyl group having from Al to 18 carbon atoms, and A is an alkylene group having 2 to 6 carbon atoms].