JPH01311114A - Production of foamed polyurethane molded article - Google Patents

Abstract

PURPOSE:To improve the filling performance, rigidity, etc., of a foamed polyurethane molded article produced by pouring an organic polyisocyanate, a polyol, a foaming agent, etc., into a mold by using a specific amount of dichlorotetrafluoroethane as a foaming agent under a specific condition. CONSTITUTION:A molded article of a foamed polyurethane is produced by pouring an organic polyisocyanate, a polyol, a surfactant, a foaming agent and a catalyst into a mold. The above expansion molding is carried out at an NCO/OH equivalent ratio of 0.9-1.4 under a condition to give a free from density of >=35g/l using 5-30 pts.wt. (based on 100 pts.wt. of the polyol) of dichlorotetrafluoroethane as a foaming agent in a state dissolved in the polyol. The produced foamed polyurethane molded article has thin wall and contains little voids and pinholes.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a polyurethane foam molded article by adding a blowing agent to a polyol, a surfactant, a catalyst, and an organic polyisocyanate.

Foamed polyurethane molded products are used as insulation materials and structural materials, and in detail, they are used in building materials such as partition panels, surface materials, and home appliance parts, as well as ceiling interior materials, door interior materials, interior door materials, bumpers, etc. for automobile parts. Used for etc.

[Conventional technology]

Foamed polyurethane molded articles are produced by adding an organic polyisocyanate, a polyol, a surfactant, a catalyst, and generally water or trichloromonofluoromethane as a blowing agent, alone or in combination, and pouring the mixture into a mold.

Foamed polyurethane molded products are lightweight and have excellent heat insulation and temperature characteristics, so they are used in a very wide range of fields. In particular, thin-walled molded products made from raw materials with a free foam density of 7 J 11/ or more are rigid, so they can be used in combination with facing materials such as aluminum plates, kraft paper, and PVC films to be used as interior and exterior materials for automobiles, decorative panels, and various equipment housings. Used for etc. However, since filling properties are poor in thin-walled molded products, (1) the density of the molded product is too high. (2)
Molded product density distribution is large. +31 void, pinhole,
Problems such as air bubbles, etc. are likely to occur. L's group tracing J\
Ka1k.

[Purpose of the invention]

An object of the present invention is to provide a foamed polyurethane molded product with excellent filling properties for producing thin-walled foamed polyurethane molded products.

The purpose of the present invention is to combine organic polyisocyanate, polyol, surfactant, blowing agent and catalyst with NCO/O
H equivalent ratio 0.9~/, free foam density, 7 s i
/ To produce a thin-walled foamed polyurethane molded product by injecting into a mold under the above conditions, 5 to 30 parts by weight of dichlorotetrafluoroethane is added as a blowing agent to 100 parts by weight of polyol. This can be achieved by dissolving it in an organic polyisocyanate or polyol.

[Structure of the invention]

The organic polyisocyanate, polyol, catalyst, and surfactant that are the raw materials for the foamed polyurethane used in the present invention do not need to be any different from conventionally known raw materials, but the following raw materials are usually used.

Examples of the organic polyisocyanate 2 include aliphatic, alicyclic,
Aromatic and heterocyclic polyisocyanates, oligomers thereof, carbodiimide-modified products, urethane-modified products, allophanate-modified products, incyanurate-modified products, etc., may be used alone or in combination of two or more thereof.

Specific examples include aliphatic polyisocyanates: ethylene diisocyanate, /, tI-tetramethylene diisocyanate, /IA
Alicyclic polyisocyanates such as -hexamethylenediyneane-), /, /2-dodecane diisocyanate; cyclobutane-1, 3-diisocyanate, cyclobutane, 3- and -/, G(-diisocyanate, etc.), aromatic Polyisocyanate (2m-phenylene diisocyanate 1.21II-tolylene diisocyanate), S, +-tolylene diisocyanate, co, V'-diphenylmethane diisocyanate, &, 4t'-diphenylmethane diisocyanate, etc., and oligomers and oligomer mixtures thereof. , carbodiimide, urethane, allophanate,
and modified products such as incyanurate. Preferably, co, V'- and p, 4t'
-Diphenylmethane diisocyanate and oligomer mixtures thereof, J, 4t- and 2,6-dodecane diisocyanate, 1,6-hexamethylene diisocyanate and oligomer mixtures thereof, and carbodiimide, urethane or allophanate modified products of these polyisocyanates is used.

As the polyol, polyether polyol and polyester polyol are used. Examples of polyether polyols include compounds having co or more active hydrogen molecules such as ethylene glycol, propylene glycol, glycerin, trimethylolpropane, pentaerythritol, methyl glucoside, sorbitol, shake rose, and bisphenol A, or jetanolamine, and triethanol. Alkamer amines such as amines, ethylenediamine, diethylenetriamine, ammonia, aniline, tolylenediamine, xylylenediamine, diaminodiphenylmethane, 3,5-diethyltolylenediamine, etc. compounds having co or more active hydrogen atoms, and/or these Polyhydroquine compounds, those obtained by adding ethylene oxide or propylene oxide to an M ring (M ring), and polytetramethylene glycol are also used.

In addition, polyester polyols are usually obtained by reacting polycarboxylic acids such as adipic acid, heptatalic acid, and trimellitic acid with polyhydric alcohols such as triethylene glycol, furopylene gelicol, tI phthanediol, trimethylolpropane, and glycerin. What is given is used.

For the production of rigid polyurethane foam molded products, although not particularly limited, molecule iA is preferred.

-t, ooo polyether polyols and polyester polyols are used as a mixture of 7 types or λ or more types.

Examples of foaming catalysts include amine compounds such as triethylenediamine, triethylamine, N-methylmorpholyl/, tetramethylethylenediamine, and tetramethylhexamethylenediamine, stannaoctoate, stannaolate,
Organic metal tin such as dibutyltin dilaurate, mercury, lead compounds, etc. are used. These are used alone or in combination, and are usually added in o, i-s, and o parts by weight per 100 parts by weight of polyol for producing foamed polyurethane.

As the surfactant, an organic silicon surfactant is usually used. Specifically, they include organic polysiloxane-polyoxyalkylene copolymers, polyalkenylsiloxanes having polyoxyalkylene side chains, and the like. Regarding the manufacturing method, chemical structure, and specific compound examples of these organosilicon surfactants, see, for example, Tokuko Sho 3! -103113, Tokuko Showa 3/s-/331111. Tokko Akira? ? -Kg! ;0,
Tokko Sho, 2g-1,000, Tokko Sho 39-/g! ;0゜Special Public Show '10-/Ko i'yo, Special Public Show 1I2-27/ri, Special Public Show 113-/1,3 wata, Special Public Show 3-/'/9
9g etc.

These can be used alone or in combination, and flame retardants and the like can be added as necessary to 100 parts by weight of the polyol for producing foamed polyurethane.

The blowing agent in the present invention is polyol io.

5 to 30 parts by weight of dichlorotetrafluoroethane (hereinafter abbreviated as F-//I) is dissolved in organic polyisocyanate or polyol. F-//l
It is more advantageous to use I in solution because the reaction proceeds more uniformly. Further, within a range that does not impair the effects of the present invention, known halogenated hydrocarbon derivatives having a boiling point of ~KA"Q, such as
Trichloromonofluoromethane (hereinafter abbreviated as F-//)
, trichlorotrifluoroethane, dichlorotrifluoroethane, dichloromethane, etc., as well as water, pentane, hexane, etc. may be used. When water is used, it is preferable to mix it in advance with the polyol in an amount equal to or less than 100 parts by weight based on 100 parts by weight of the polyol.

A predetermined amount of an organic polyisocyanate with an NCO/OH equivalent ratio of 0.9 to 1/I is added to a predetermined amount of polyol, catalyst, surfactant, and blowing agent, which are raw materials for polyurethane foam, using a normal reaction injection molding machine (RIM molding). Machine: Reacti
on 1. The foamed polyurethane is injected into the mold using MolcLing to obtain a foamed polyurethane molded product.

The temperature of the raw material in the RIM molding machine is normally adjusted to 75 to 35°C.

The above foamed polyurethane raw materials were mixed and injected into a mold whose temperature was adjusted to 30 to 60°C. Remove the molded product from the mold in 20 minutes.

At this time, glass fiber such as continuous strand mat or chopped strand mat may be placed inside the mold.

In the present invention, the free foam density is 3! By molding a thin-walled product under the above conditions, a molded product with high rigidity, excellent filling properties, and few voids and pinholes can be obtained.

This invention is! It is particularly effective in producing thin-walled polyurethane molded articles with a thickness of less than Orrrm, preferably less than 20 m, more preferably 2 to 10 m.

〔Example〕

Examples of the present invention are shown below, but the present invention is not limited to these Examples.

The filling property was evaluated using a RIM molding machine using ioqθ■×
lOri! r rm X 3 rm or jm or 91
A 1111 aluminum mold was heated to 0'C or 50°C, one end of the mold was injected through a 1.51III+ film gate, and the density was calculated by dividing the polyurethane foam mold volume by the mold volume (Just Pack Density). (abbreviated as 2 or less)
This was done by measuring.

Here, the term "minimum filled polyurethane foam" means the weight of the polyurethane foam that fills the entire volume of the mold when it is injected into the mold.

Furthermore, the ratio between the free foam density (hereinafter abbreviated as DF) and the minimum filled foamed polyurethane molded article density (DJ) was calculated.

Minimum filled polyurethane foam molded product Light weight DJ/DF
The smaller the value is, the better the filling property is, and the larger the DJ/DF value is, the worse the filling property is.

Example/-G (and Comparative Examples 1 to 3) The following foamed polyurethane was used in the same manner, except that water, l:''-//'I, and F-// were used as blowing agents in the proportions shown in Table-l. A foamed polyurethane molded article was obtained using the raw material composition.The mold conditions and the physical properties of the molded article are also listed in Table-1.

Anate (hereinafter abbreviated as C-MDI) N■ Content: 30 to 3λ Thipolyol; 70 parts by weight of sucrose polymer Robylene ochid adduct Hydroxyl value lIo.

Propylene of glycerin 30 parts by weight Len-Oquinde adduct Hydroxyl value St, 0 NCO10H equivalent ratio; /, /3 Surfactant; Organosilicon surfactant 3 parts by weight Polymer catalyst: Tetramethyl hexa 3 parts by weight Methylenediamine filler; Conti Near Strand Matte Glass Fiber (C3M-GF) [Effects of the Invention] According to the present invention, the DJ/DF value shown in the above example for a thin-walled polyurethane foam product is below q,
1) Excellent filling properties; (2) low overfilling rate, resulting in low foaming pressure; and (3) excellent thin-walled molded products with few voids and pinholes.

Furthermore, even in the case of reinforced foamed polyurethane molded products in which C8M-C;

Applicant: M.D. Kasei Co., Ltd. Agent Patent Attorney Hase - 1 other person

Claims (1)

[Claims] (1) Organic polyisocyanate, polyol, surfactant, blowing agent, and catalyst at an NCO/OH equivalent ratio of 0.9 to
1.4. When producing a foamed polyurethane molded product by injecting it into a mold under conditions of a free foam density of 35 g/l or more,
5 to 30 parts by weight of polyol as a blowing agent
1. A method for producing a foamed polyurethane molded article, characterized in that part by weight of dichlorotetrafluoroethane is dissolved in an organic polyisocyanate or a polyol.