JPH06206977A - Hybrid cross-linkable resin composition good in storage stability and method for molding the same - Google Patents

Abstract

PURPOSE:To provide a hybrid cross-linkable resin composition excellent in heat resistance, rigidity, reactivity, impact resistance and productivity, useful for molding products, etc., comprising each specific resin component and aromatic polyisocyanate component at specified proportion. CONSTITUTION:The composition comprising (A) a resin component made up of (1) as the main component, a mixture of (a) a hydroxyl group-terminated unsaturated polyester <=3mgKOH/g in acid value and 90-150mgKOH/g in OH value and (b) a vinyl compound, (2) 0.3-1.0wt.% of cobalt naphthenate and (3) 0.1-0.3wt.% of acetylacetone and (B) an aromatic polyisocyanate component (e.g. phenylene diisocyanate) incorporated with 2.0-8.0wt.% of an organic peroxide, a peroxyester such as t-butyl peroxylaurate at the equivalent ratio OH/NCO of (1:0.8) to (1:1.5). In this composition, ester-amidation between the OH group and the NCO group and free radical cross-linking reaction by the unsaturated group can simultaneously be carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition having heat resistance and high rigidity of an unsaturated polyester resin and high-speed reactivity and impact resistance of a polyurethane resin at the same time, and a reaction injection molding method thereof. The present invention provides a composition which stably exists as a mold resin composition and is extremely easy to handle during storage or molding process, and a molding method thereof.

[0002]

2. Description of the Related Art Conventionally, unsaturated polyester resins have been widely used in housing equipment such as bathtubs and water storage tanks, ships, industrial fields, leisure fields, etc. due to their excellent rigidity and heat resistance. Due to the long molding and curing time, the development to automobile parts is relatively small except for the sheet molding compound (SMC). On the other hand, polyurethane resin is widely used for automobile parts such as bumpers by reaction injection molding method (RIM method) due to its excellent impact resistance and high-speed reactivity, but it is used because of its insufficient strength. The types of parts used were limited.

Therefore, it has been attempted to combine an unsaturated polyester resin and a polyurethane resin to make up for the defects of the two and to produce a resin having a new structure. For example, a technique of producing a tough SMC by reacting a low acid value isophthalic acid unsaturated polyester with liquid MDI (Japanese Patent Laid-Open No. Sho 5).
No. 5-73718), a technique for obtaining an insoluble and infusible thermosetting product from esterol and TDI by using the RIM method (Japanese Patent Laid-Open No. 58-91719), a rapid method from hydroxyacrylate and MDI. Technology for carrying out in-mold polymerization (Japanese Patent Laid-Open No. 57-182312), impact resistance excellent in molding speed and linear expansion coefficient by using RIM molding method from isophthalic unsaturated polyester containing terminal OH group and liquid MDI. Technology (Composites-No3-May-Juin 1987) that a hybrid resin having high resistance and abrasion resistance is obtained has been reported.

However, in the molding method by the RIM method, it is a two-liquid component system, and the resin component and the isocyanate component are respectively charged into the machine tank, and the raw material components once charged into the machine tank are used in the entire amount on that day. Is the premise, but it may remain. As a further inconvenient case, there is a case where the product stays in the machine tank for about two weeks due to a long stoppage. Therefore, the resin component and aromatic polyisocyanate component once blended should be stable for at least 2 weeks or more and should not change in quality. Furthermore, the isocyanato group reacts with moisture in the air and causes deterioration of quality, so normally avoid mixing other components in the molding process, accept the pre-blended aromatic polyisocyanate from the manufacturer, and use it as is. Is common. On the other hand, since the resin component is not sensitive to moisture in the air, generally, in the urethane industry, other components are blended with the resin component, and if there is a storage stability of about 2 weeks or more, There is no hindrance in producing molded products. Therefore, when receiving the pre-blended resin component, it is desirable that the resin has storage stability of 2 weeks or more, preferably about 1 month.

In the unsaturated polyester / urethane hybrid cross-linking type resin, the presence of an organic peroxide and its decomposition accelerator which accelerate radical polymerization in the mold (mold temperature 50 to 70 ° C.) simultaneously with the urethane formation catalyst. is necessary. Combinations of organic peroxides and their decomposition promoters have been known for a long time, and the most famous combinations among them are benzoyl peroxide and dimethylaniline and methyl ethyl ketone peroxide and cobalt naphthenate. However, benzoylper-oxide is decomposed in isocyanate, and the urethanization reaction between the isocyanato group and the OH group is excluded in 20 to 25 ° C. in 2 to 3 days, and hybrid crosslinking cannot be performed. In addition, methyl ethyl ketone peroxide reacts with an isocyanato group to cause gelation only when it is added to an aromatic polyisocyanate. Dialkyl peroxides are stable in aromatic polyisocyanates, but no suitable decomposition accelerator has been found. Further, cumene hydroperoxide, which has a very good thermal stability, also has a drawback that it reacts in an aromatic polyisocyanate.

For the above reasons, the practical method of using the hybrid cross-linking type is so-called 3 in which the organic peroxide is added to the isocyanate at the time of use and all is used up after being added to the machine tank. The liquid type (resin component, aromatic polyisocyanate component and curing agent component) had to be used, and the handling of raw materials and the blending work were complicated and became a problem. That is, it has been desired to develop a stable raw material that can be used by directly feeding the raw material delivered in the two-pack type into the machine tank.

[0007]

The problem to be solved by the present invention is to provide a hybrid crosslinkable resin composition having good storage stability, and as an organic peroxide, it is stable to temperature, impact, etc., and Stable presence in aromatic polyisocyanate, decomposition promoter of organic peroxide, stable in temperature, humidity, etc., and stable in resin component, further decomposition accelerator To provide a two-component hybrid crosslinkable resin composition that satisfies the conditions such as having stability such that it does not react with other components when added to a resin component, and a molding method thereof. .

[0008]

DISCLOSURE OF THE INVENTION The inventors of the present invention have proposed, as a hybrid crosslinkable resin, a two-part hybrid having good storage stability in which an organic peroxide and its decomposition accelerator are added in advance to an isocyanate component and a resin component, respectively. As a result of extensive studies aimed at obtaining a crosslinkable resin, it was found that the use of a specific combination of an organic peroxide and a decomposition accelerator has a storage stability of 1 month or more, and the present invention is completed. I arrived.

That is, according to the present invention, 1) an acid value of 2 mgKOH / g or less and an OH value of 90 to 150 m
The main component is a mixture of unsaturated polyester containing terminal hydroxyl group of gKOH / g and vinyl compound, and 0.3 to 1.0% by weight of cobalt naphthenate and 0.1 to 0.3% by weight of acetylacetone are added to the mixture. 1. Resin component (1) and peroxy ester which is an organic peroxide 2.
In the aromatic polyisocyanate component (2) containing 0 to 8.0% by weight, the equivalent ratio of the hydroxy group and the isocyanate group is OH / NCO = 1 / 0.8 to 1 / 1.5. Good storage stability, characterized by being used in proportion,
A hybrid cross-linking resin composition capable of advancing a urethanization reaction of a hydroxy group and an isocyanato group and a radical cross-linking reaction by an unsaturated group substantially at the same time. 2) The resin composition according to 1), wherein t-butylperoxylaurate is used as the peroxyester. 3) Acid value 2 mgKOH / g or less, OH value 90 to 150 m
The main component is a mixture of unsaturated polyester containing terminal hydroxyl group of gKOH / g and vinyl compound, and 0.3 to 1.0% by weight of cobalt naphthenate and 0.1 to 0.3% by weight of acetylacetone are added to the mixture. 1. Resin component (1) and peroxy ester which is an organic peroxide 2.
In the aromatic polyisocyanate component (2) containing 0 to 8.0% by weight, the equivalent ratio of the hydroxy group and the isocyanate group is OH / NCO = 1 / 0.8 to 1 / 1.5. Molding of a hybrid cross-linking resin characterized in that a reaction injection molding machine is used in a ratio to cause a urethane-forming reaction between a hydroxy group and an isocyanato group and a radical cross-linking reaction due to an unsaturated group to proceed substantially simultaneously. Law. 4) t-butylperoxylaurate is used as the peroxy ester, and the molding method according to 3). Is.

The unsaturated polyester containing a terminal hydroxy group that can be used in the present invention is, for example, maleic acid,
Α, β unsaturated dibasic acids such as fumaric acid, itaconic acid, citraconic acid or their anhydrides, and if necessary phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, tetrahydrophthalic acid Acid, a mixture with a dibasic acid such as chlorendic acid, a condensation reaction product of esterification by reacting glycols such as ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, neopentyl glycol, etc. by a conventional method. . The vinyl compounds include styrene, vinyltoluene, divinylbenzene, methyl methacrylate, diallyl phthalate, etc. These vinyl compounds are usually diluted in the form of a diluent in the resin component in an amount of about 15 to 50% by weight. Used. The most preferred unsaturated dibasic acid is maleic anhydride and the optional dibasic acid is isophthalic acid. As glycols, ethylene glycol, diethylene glycol and the like are preferable.

The molar ratio of dibasic acid and glycol is dibasic acid / glycol = 1 / 1.2 to 1 / 1.5 and esterified by a conventional method to give an acid value of 2 mgKOH / g or less, more preferably 1 mgKOH. The reaction is terminated when it becomes less than / g. At this time, the hydroxyl value is 100 to 150 mgKOH
/ Mg range. After the reaction, viscosity is 1000 cp
Dilute with vinyl compound so that the temperature becomes s / 25 ° C or lower. The most preferred vinyl compound is styrene.

When the acid value is 2 mgKOH / g or more, the urethane-forming reaction is delayed during the hybrid crosslinking reaction, and a good molded product cannot be obtained. Hydroxyl value is 100mgK
When it is OH / g or less, the viscosity becomes high and the dilution rate with styrene increases, so that only a brittle molded product can be obtained. When the hydroxyl value is 150 mgKOH / g or more, the unsaturated polyester has a small molecular weight and only a soft molded product can be obtained.

Aromatic polyisocyanates that can be used in the present invention include phenylene diisocyanate,
Tolylene diisocyanate (TDI), 4,4′-methylenebis (phenylisocyanate) (MDI), carbodiimide-modified liquid MDI, terminal NCO urethane-modified MDI produced by reaction with a polyol compound, polymethylene polyphenylene polyisocyanate (crude M)
DI) and the like. Most preferred is a carbodiimide modified liquid MDI.

The organic peroxide which can be used in the present invention is a peroxy ester type, and includes t-butylperoxy 2-ethylhexanoate, t-butylperoxylaurate and t-butylperoxide. Examples include oxybenzoate. The most preferred peroxyester is t-butyl peroxylaurate. The amount of t-butylperoxylaurate added to the aromatic isocyanate is 2.0 to 8.0% by weight. If the addition amount is 2.0% by weight or less, radical cross-linking is insufficient during the hybrid cross-linking reaction, and a good molded product cannot be obtained. On the other hand, if it is 8.0% by weight or more, the promoting effect of the radical crosslinking reaction is no longer saturated, and even if it is added, a better effect cannot be obtained, and it becomes a factor to delay the radical crosslinking reaction.

The decomposition accelerator usable in the present invention is a combination system of cobalt naphthenate and acetylacetone. The amount of cobalt naphthenate added is 0.4 to 1.
2% by weight, more preferably 0.6 to 1.0% by weight
Is. If it is 0.4% by weight or less, radical cross-linking is insufficient during a hybrid cross-linking reaction, and a good molded product cannot be obtained. When it is 1.2% by weight or more, the storage stability is significantly reduced. The amount of acetylacetone added is 0.1 to 0.3% by weight of the resin, and more preferably 0.15.
˜0.25% by weight. If it is less than 0.1, a good molded product cannot be obtained because the radical crosslinking is insufficient during the hybrid crosslinking reaction. If it is 0.3% by weight or more, it interferes with cobalt naphthenate and crystals are deposited to cause alteration.

Another component that can be used in the present invention is a urethanization catalyst, examples of which include tin catalyst such as dibutyltin dilaurate (DBTDL) and bismuth catalyst (COSCAT # 83, Shepherd Chemical Co.). . In addition, a low molecular weight glycol or the like can be added if necessary. As low molecular weight glycol, ethylene glycol, trimethylolpropane, glycerin,
Examples thereof include alkylene oxides. Other auxiliary agents include surfactants, surface modifiers, pigments, internal release agents, inorganic fillers, unsaturated polyester industry, RI
Those generally used in the M urethane industry and the like can be used.

The resin composition of the present invention thus obtained is composed of a resin component and an aromatic polyisocyanate component.
It is a liquid raw material system and is injection-molded in a mold by the RIM method. If necessary, the mold can be filled with a reinforcing material. A continuous strand mat is effective as a reinforcing material. Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

[0018]

EXAMPLES The present invention will be described below with reference to examples. The results of Examples and Comparative Examples are summarized in Tables 1 and 2.

[0019]

[Table 1]

[0020]

[Table 2]

First, a mixture of an unsaturated polyester resin as a resin component and a vinyl compound was produced as follows. In a reactor equipped with a stirrer, thermometer, partial condenser, maleic anhydride 42.0 kg, isophthalic acid 3
After adding 5.6 kg, ethylene glycol 21.5 kg, and diethylene glycol 59.9 kg, the system was replaced with nitrogen gas. The temperature was raised and the reaction was allowed to proceed at 210 ° C. for 14 hours. At this time, the acid value was 0.8 mgKOH / g and the hydroxyl value was 110 mgKOH / g. Next, 143.6 kg of this unsaturated polyester resin was mixed with styrene 47.9.
kg and 38.3 g of hydroquinone were added to obtain a product.

Examples 1 and 2 Comparative Examples 1 and 2 A mixture of the above-mentioned unsaturated polyester resin containing a terminal hydroxy group and a vinyl compound as a resin component, and a carbodiimide-modified liquid MDI as an aromatic isocyanate component.
(Mitsui Toatsu Chemicals, trade name Cosmonate LK, all NC
O 28.3%) was blended in a ratio shown in Table 1 to examine the storage stability. The storability was measured by storing the sample in a room at 23 ° C., mixing and stirring the components at regular intervals according to the mixing ratio, and examining the reactivity. The results are shown in Table 1. In Comparative Example 1, the amount of acetylacetone was increased, and in Comparative Example 2, the most commonly used benzoyl peroxide / dimethylaniline system, the reaction activity was extremely high. On the other hand, in Examples 1 and 2 of the present invention, it can be seen that the reaction activity does not decrease even after 40 days have passed since the compounding.

Example 3 The resin component and the isocyanate component used in Example 1 were charged into a machine tank of a high-pressure foaming machine LMR-228 manufactured by Toho Machine Industry Co., Ltd., and injection-molded into a mold under the conditions shown in Table 2. . The mold was a sheet mold of 535 × 200 × 3 mm and kept at 70 ° C. A continuous strand mat (Unifilo U-816, basis weight 375 g / m ² manufactured by Nippon Electric Glass Co., Ltd.) was set in the mold so as to have a predetermined amount.
The obtained hybrid crosslinked resin molded product showed excellent physical properties as shown in Table 2.

[0024]

The hybrid crosslinkable resin composition of the present invention has a long-term storage stability as a two-part type and is extremely easy to handle in storage and molding operations. Further, the molded product formed by RIM molding using the hybrid cross-linking resin composition of the present invention has high-speed moldability and excellent physical properties.

Claims (4)

[Claims] 1. An acid value of 2 mgKOH / g or less and an OH value of 90.
˜150 mg KOH / g of a terminal hydroxy group-containing unsaturated polyester and a vinyl compound as a main component,
Resin component (1) containing 0.3 to 1.0% by weight of cobalt naphthenate and 0.1 to 0.3% by weight of acetylacetone, and peroxyester of 2.0 to 8 which is an organic peroxide. The aromatic polyisocyanate component (2) contained in an amount of 0.0% by weight has an equivalent ratio of hydroxy groups and isocyanate groups of OH / NCO = 1 / 0.8 to 1 / 1.5.
Hybrid cross-linking, which has good storage stability and is capable of proceeding substantially simultaneously with the urethanization reaction of a hydroxy group and an isocyanato group and the radical cross-linking reaction with an unsaturated group. Type resin composition. 2. The resin composition according to claim 1, wherein t-butylperoxylaurate is used as the peroxyester. 3. An acid value of 2 mgKOH / g or less and an OH value of 90.
˜150 mg KOH / g of a terminal hydroxy group-containing unsaturated polyester and a vinyl compound as a main component,
Resin component (1) containing 0.3 to 1.0% by weight of cobalt naphthenate and 0.1 to 0.3% by weight of acetylacetone, and peroxyester of 2.0 to 8 which is an organic peroxide. The aromatic polyisocyanate component (2) contained in an amount of 0.0% by weight has an equivalent ratio of hydroxy groups and isocyanate groups of OH / NCO = 1 / 0.8 to 1 / 1.5.
A hybrid cross-linking resin characterized by being used at a ratio of 1 to 3 and using a reaction injection molding machine to substantially simultaneously proceed a urethanization reaction between a hydroxy group and an isocyanato group and a radical cross-linking reaction due to an unsaturated group. Molding method. 4. The molding method according to claim 3, wherein t-butylperoxylaurate is used as the peroxyester.