JP3165142B2 - Manufacturing method of rigid urethane foam with skin material - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a composite comprising a polyvinyl chloride resin and a polyurethane foam using a vinyl chloride resin as a skin material. More specifically, the present invention relates to a method for producing a composite of a polyvinyl chloride resin skin and a polyurethane foam using a rigid urethane foam having improved performance and excellent adhesion to a vinyl chloride resin.

[Conventional technology]

For the composite of polyvinyl chloride resin skin and polyurethane foam used as interior materials and furniture components of automobiles, a vinyl chloride resin skin molded in advance by powder slush molding method, etc. is laid on a mold and mixed with foamable urethane. It is obtained by pouring the liquid, sealing the mold and curing.

[Problems to be solved by the invention]

The composite obtained in this way sometimes suffers from peeling when some external force is applied during the manufacturing process due to insufficient adhesion at the initial stage of molding the vinyl chloride resin and urethane foam composite. Often lose value. Therefore, polyester polyols have been added to the stock solution on the polyol side used for polyurethane foam production in order to increase the adhesiveness.

In the composite of vinyl chloride resin and urethane foam, which has been used as a material for interior materials and furniture of automobiles in the past, most of polyurethane foam is a flexible semi-rigid foam. Replacement of structural materials that have been manufactured using ABS resin etc. with rigid urethane foam to respond to the complexity of the design and demand for weight reduction due to the upgrading of components, using a combination of vinyl chloride resin and rigid urethane foam Attempts have been made to create products with the same functions as before. Furthermore, to protect the earth's ozone layer, fully halogenated fluorocarbons (CFC
The use of CFCs was restricted, and the use of CFCs, which was indispensable for foaming rigid urethane foam, had to be reduced. Water and polyisocyanate instead of CFCs The carbon dioxide generated by the above reaction is being used as an alternative blowing agent. Under these conditions, when producing a composite of a vinyl chloride resin and urethane foam, the viscosity of the polyol side stock solution for foaming becomes high because CFCs, which have been conventionally used as a foaming agent, are not used, and the polyisocyanate is used. It is difficult to obtain a foam having uniform and fine cells, having no unevenness on the surface, and free from defects such as blisters even at high temperatures. Also, when a polyester polyol effective for improving the adhesion between the vinyl chloride resin and the rigid urethane foam is added to the polyol-side undiluted solution, the undiluted solution becomes cloudy and the separation may occur even when the temperature is changed or the storage is performed for a short time. Production was difficult. In order to prevent turbidity and separation, a component that increases compatibility may be added, but in such a case, unfavorable performance of the product such as a decrease in the strength of the rigid foam may occur.

[Means for solving the problem]

The present inventors have conducted intensive studies to solve these problems, and as a result, a polyisocyanate containing a prepolymer having a terminal NCO group, which is a reaction product of an aromatic polyisocyanate and a polyester polyol, as an isocyanate component. In the case of foaming mainly composed of carbon dioxide generated from the reaction between water and isocyanate components, the mixing properties of both polyisocyanate and polyol stock solutions are good, a uniform cell structure is achieved, and adhesion to vinyl chloride resin is achieved. It has been found that a good composite can be obtained, which has led to the present invention.

 That is, the present invention is as follows.

Polyisocyanate, polyol, water, catalyst, foam stabilizer, halogenated hydrocarbon foaming agent if necessary, filler,
In addition to mixing the other additives and contacting with the skin material to foam-form the rigid polyurethane foam, the polyisocyanate is a prepolymer of aromatic polyisocyanate and polyester polyol alone or contains the skin material. A method for producing a rigid urethane foam.

Hereinafter, the present invention will be described in more detail. The polyisocyanate (A) used in the present invention is a prepolymer of an aromatic polyisocyanate (a) and a polyester polyol (b) or a prepolymer containing the same. Aromatic polyisocyanates include 2,4-tolylene diisocyanate, 2,6
-Tolylene diisocyanate, a mixture of 2,4- and 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenylene polyisocyanate, naphthylene diisocyanate and the like.

The polyester polyol is obtained by a reaction between a dibasic acid and a polyol, and the dibasic acid is an aliphatic dicarboxylic acid, an aromatic dicarboxylic acid, or an alicyclic dicarboxylic acid. Acid, glutaric acid, adipic acid, pimelic acid, corkic acid,
Azelaic acid, sebacic acid, dodecane dicarboxylic acid, etc., as aromatic dicarboxylic acids, for example, phthalic anhydride, isophthalic acid, terephthalic acid, etc., as alicyclic dicarboxylic acids, cyclohexane-1,4-dicarboxylic acid, cyclohexane 1,2-dicarboxylic acid, hexahydrophthalic anhydride and the like. As the polyol, a diol having a structure of the following general formula shown in JP-B-53-015865 having two or more hydroxyl groups in a molecule or a mixture of this diol and another aliphatic polyhydric alcohol is preferable. .

General formula (In the formula, R represents a hydrogen atom or an alkyl group having 1 or more carbon atoms.) Examples of the diol having the structure of the above general formula used in the present invention include neopentyl glycol, 2,2,4-
Trimethyl-1,3-pentanediol and the like. Other aliphatic polyhydric alcohols shared with the diol represented by the above general formula include, for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene glycol, 1,4-butylene glycol , Trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, sorbitol, polyethylene glycol, polypropylene glycol, polybutylene glycol, castor oil and the like.

By incorporating the prepolymer into the polyisocyanate component, a uniform foam having good compatibility with the polyol component can be obtained, and the adhesive strength between the vinyl chloride resin and the foam can be significantly improved.

The prepolymer is used as it is or as a mixture with an aromatic polyisocyanate. The NCO group content of the polyisocyanate containing the prepolymer is suitably from 25 to 30% by weight. Until that point, the viscosity of the polyisocyanate containing the prepolymer increases, and the effect of improving the compatibility with the polyol component is impaired by the prepolymer. If it exceeds 30% by weight, the effect of the prepolymer is small.

The polyol (B) used in the present invention has 2 to 8 functional groups.
80 to 95% by weight of a polyol having a hydroxyl value of 300 to 700 mg KOH / g or a mixture of two or more polyols (c)
And a polyol (d) having 20 to 5% by weight having 2 to 4 functional groups and a hydroxyl value of 837 to 2,000 mgKOH / g. Polyols having a functional group number of 2 to 8 and a hydroxyl value of 300 to 700 mgKOH / g include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerol, 1,2,6-hexanetriol, trimethylolpropane, monoethanolamine and diethanolamine. ,
Compounds having active hydrogen such as triethanolamine, pentaerythritol, α-methylglucoside, ethylenediamine, tolylenediamine, 4,4'-diaminodiphenylmethane, diethylenetriamine, sorbitol, sucrose, and alkylene such as ethylene oxide, propylene oxide, and butylene oxide Polyether polyols obtained by adding oxides, or mixtures of these polyether polyols, or polyester polyols obtained by condensation of polyols with polycarboxylic acids, PET
Aromatic polyester polyols and the like obtained by heat-treating various residues of resins and PET resin production processes with polyols such as diethylene glycol. The hydroxyl value of the polyol is from 300 to 700 mgKOH / g. If it is less than this, the strength of the foam is insufficient, and if it exceeds 700 mgKOH / g, the foam becomes brittle and none of them can be put to practical use.

The number of functional groups is 2 to 4 and the hydroxyl value is 837 to 2,000 mgKOH /
As the polyol of g, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerol, diethanolamine, triethanolamine, trimethylolpropane, pentaerythritol, and their alkylene oxide adducts can be used. Hydroxyl value 837-2,000 with 2-4 functional groups
If the mgKOH / g polyol exceeds 20% by weight of the total polyol, the foam becomes brittle, and if it is less than 5% by weight, the foam becomes soft, and neither is preferred.

The catalyst used in the present invention is a tertiary amine compound or an organometallic compound. Tertiary amines include, for example, triethylamine, triethylenediamine, N-methylmorpholine, N-ethylmorpholine, N, N-dimethylaminoethanol, N, N-dimethylcyclohexylamine, N, N, N ', N'- Tetramethylethylenediamine, N,
N, N ', N'tetramethylpropylenediamine, N, N, N',
N'-tetramethylbutylenediamine, N, N, N ', N'-tetramethylhexamethylenediamine, N, N, N', N ', N "
-Pentamethyldiethylenetriamine and the like can be used alone or in combination. As the organometallic compound,
For example, there are dibutyltin dilaurate, stannous octoate and the like, and these can be used alone, as a mixture, or as a mixture with the above tertiary amine compound.

In the present invention, a foam stabilizer is used for cell stability. As the foam stabilizer, a silicone polyether copolymer is generally used. For example, L-5420, L-5421, L-5340 <Nippon Unicar Co., Ltd.
These include SH-190 and SH-193 of Toray Silicone Co., Ltd., F-305, F-317, F-341 and F-345 of Shin-Etsu Chemical Co., Ltd., and TFA-4200 of Toshiba Silicone Co., Ltd.

In the present invention, carbon dioxide generated from the reaction between water and isocyanate is mainly used as the blowing agent. The amount of water depends on the density of the product, but is usually based on 100 parts by weight of polyol.
0.5 to 5.0 parts by weight. Incidentally, chlorofluorocarbons which have been conventionally used as a foaming agent, or halogenated hydrocarbons having a hydrogen atom in the molecule can also be used supplementarily.

In the composite of the present invention, a sheet-like skin material of a soft vinyl chloride resin is laid in a mold made of metal or resin, and a mixture of a polyol, water, a catalyst, a foam stabilizer and a polyisocyanate component are placed thereon. The mixture is poured into the mixture, the mold is closed, and the mixture is left for a predetermined period of time to produce the mixture.

Rigid urethane foam of the present invention is a so-called hand-mix method using a rotating blade type agitator after putting a polyol stock solution and a polyisocyanate stock solution in one container,
It can also be manufactured by a so-called mechanical foaming method using a foaming machine having a low-pressure or high-pressure mixing device.

As the skin material of the composite, sheets of vinyl chloride resin softened by adding a plasticizer are used. In particular, a skin material formed by a powder slush method having good design properties is preferably used.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples. The percentages used in the examples are on a weight basis unless otherwise specified.

Description of the raw materials A mixture of TDI 80/20: 2,4-TDI and 2,6-TDI 80:20 (weight). Manufactured by Mitsui Toatsu Chemical Co., Ltd.

MDI-CR 200: polymeric MDI. NCO content 31.0%, viscosity
190 cps / 25 ° C. Manufactured by Mitsui Toatsu Chemical Co., Ltd.

Polyester polyol- (1): 2,2,4-trimethyl-
Polyester polyol obtained from a mixture of 1,3-pentanediol, castor oil and pentaerythritol, sebacic acid and phthalic anhydride. Hydroxyl value 148mgKOH / g.

Polyester polyol- (2): Polyester polyol obtained from neopentyl glycol, 1,3-butylene glycol, trimethylolpropane and adipic acid. Hydroxyl value 172 mgKOH / g.

Polyester polyol- (3): Polyester polyol obtained from neopentyl glycol and adipic acid. Hydroxyl value 172 mgKOH / g.

Polyether polyol- (1): Polyether polyol obtained by adding propylene oxide to glycerol. Hydroxyl value 500 mgKOH / g.

Polyether polyol- (2): Polyether polyol obtained by adding propylene oxide to an equal weight mixture of glycerol and sucrose. Hydroxyl value 450 mgKOH / g.

Polyisocyanate- (A): reaction product of TDI 80/20 and polyester polyol- (1). NCO content 44%.

Polyisocyanate- (B): reaction product of MDI-CR 200 and polyester polyol- (2). NCO content 30
%.

Polyisocyanate- (C): Reaction product of MDI-CR 200 and polyester polyol- (3). NCO content 29%.

Polyisocyanate- (D): Reaction product of MDI-CR 200 and polyether polyol- (2). NCO content 30%.

Polyether polyol- (A): a polyether polyol obtained by adding propylene oxide to a mixture of sucrose and glycerol in a ratio of 4: 6 (by weight). Hydroxyl value 480.

Polyether polyol- (B): A polyether polyol obtained by adding propylene oxide to a mixture of α-methylglucoside and trimethylolpropane at a ratio of 6: 4 (weight). Hydroxyl value 450.

TMHD: N, N, N ', N'-tetramethylhexamethylenediamine.

L-1020: 33% dipropylene glycol solution of triethylenediamine.

L-5420: silicone-based foam stabilizer. Made by Nippon Unicar.

Example 1 100 g of polyether polyol- (A), 1.0 g of water, 7.0 g of ethylene glycol, 1.0 g of foam stabilizer L-5420, catalysts N, N,
N ', N'-tetramethylhexamethylenediamine (TMH
D) 0.3 g and 2.0 g of Catalyst Minico L-1020 (a 33% solution of triethylenediamine in dipropylene glycol) were mixed to obtain a polyol component. Polyol isocyanate- (A) / polyisocyanate- (D) = 20/80
(Weight) The mixture was mixed with 181.9 g of the mixture and subjected to free foaming and mold foaming. In free foaming, the time when foaming starts (hereinafter referred to as cream time), the time the foam draws a thread when the stick is pierced into the foam and the bar is pulled up (hereinafter referred to as gel time), and one day after foaming The foam was cut, and the foam density and the state inside the foam (cells, stripes) were observed. 45-50 ° C in advance for mold foaming
Adjusted to the lower mold of aluminum mold with average thickness 10mm,
After slush molding vinyl chloride resin was installed, a predetermined amount of urethane stock solution was injected, the upper mold was closed, and the mixture was left at room temperature for 4 minutes. The molded product was removed from the mold, and after 1 hour from the mold release,
After 3 hours, the adhesion between the slush molded vinyl chloride resin and urethane was measured using a push bull tester (IMADA push-pull sca
le).

 The results are shown in Table 1.

The foam state in free foaming was such that cells were fine and uniform without any stripes, and the adhesiveness in mold foaming was such that the slush-molded vinyl chloride resin was broken after 3 hours from the mold release.

Examples 2 to 5 The polyether polyol or polyisocyanate of Example 1 was changed. The results of the experiment are shown in Table 1. As shown in Table 1, the foam state in free foaming was uniform and thin with no cells, and no stripes. The adhesion between the slush-molded vinyl chloride resin and the urethane by foaming was also good.

Comparative Example 1 100 g of polyether polyol- (A), 1.0 g of water, 7.0 g of ethylene glycol, 1.0 g of foam stabilizer L-5420, catalysts N, N,
N ', N'-tetramethylhexamethylenediamine (TMH
D) 0.3 g and 2.0 g of Catalyst Minico L-1020 (a 33% solution of triethylenediamine in dipropylene glycol) were mixed to obtain a polyol component. The polyol component was mixed with polyisocyanate- (D), subjected to free foaming and mold foaming, and subjected to the same treatment as in the example. The results are shown in Table 1. The state of the foam in the free foaming was such that the cells were rough and had stripes, and the adhesiveness between the slush-molded vinyl chloride resin and the urethane in the mold foaming was not satisfactory.

Comparative Example 2 The polyether polyol- (A) of Comparative Example 1 was changed to a polyether polyol- (B). The results of the execution are shown in Table 1, and the foam state in free foaming and the slash in mold foaming are shown in Table 1. The adhesion between the molded vinyl chloride resin and urethane was not satisfactory either.

[Effects of the Invention] According to the present invention, in forming a composite of a rigid urethane foam and a vinyl chloride resin having water and carbon dioxide generated from isocyanate as a main blowing agent, there is no separation of a stock solution and the like, It is possible to obtain a composite of urethane foam and vinyl chloride resin having good properties and uniform foam cells.

Continuation of the front page (51) Int.Cl. ⁷ Identification code FI C08L 75:04 (56) References JP-A-62-146909 (JP, A) JP-A-62-148516 (JP, A) JP-A-62 JP-A-135511 (JP, A) JP-A-60-26041 (JP, A) JP-A-64-20222 (JP, A) JP-A-62-177013 (JP, A) (58) Fields investigated (Int. . ^7, DB name) C08G 18/00 - 18/87 CA (STN ) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. A rigid polyurethane foam obtained by mixing a polyisocyanate, a polyol, water, a catalyst, a foam stabilizer, and, if necessary, a halogenated hydrocarbon foaming agent, a filler, and other additives, and contacting the mixture with a skin material. In the foam molding of (A), the polyisocyanate is composed of the aromatic polyisocyanate (a) and the general formula (I) Wherein R represents a hydrogen atom or an alkyl group having 1 or more carbon atoms, or a mixture of the diol and another aliphatic polyhydric alcohol with a dibasic acid. (B) a mixture of one or two or more polyols having a functionality of 2 to 8 and a hydroxyl value of 300 to 700 mg KOH / g. ~ 95% by weight
A polyol (d) having 2 to 4 functional groups and a hydroxyl value of 837 to 2,000 mgKOH / g, and a mixture of 20 to 5% by weight of a rigid polyurethane foam with a skin material. 2. The production of a rigid polyurethane foam with a skin material according to claim 1, wherein the NCO group content of the prepolymer of the aromatic polyisocyanate and the polyester polyol alone or the polyisocyanate containing the same is 25 to 30% by weight. Method.