JPH0822908B2 - High molecular weight unsaturated polyester resin - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention has a number average molecular weight of 5,000.
The present invention relates to the above unsaturated alkyd and the unsaturated polyester resin obtained therefrom.

[0002]

2. Description of the Related Art Generally, α, β-unsaturated polybasic acid or its acid anhydride, typically maleic anhydride,
Fumaric acid, saturated polybasic acid or unsaturated cycloaliphatic polybasic acid or its acid anhydride is used together, and unsaturated alkyd obtained by esterification with polyhydric alcohols is dissolved in a monomer copolymerizable therewith. It is well known to make unsaturated polyester resin. This unsaturated polyester resin is a fiber reinforced plastic (F
RP), paints, casting, etc. are used in a very wide range, and the production amount reaches to over 200,000 tons per year. Thus, although it is an industrially important unsaturated polyester resin, the number average molecular weight of the unsaturated alkyd, which is a direct constituent thereof, is at most 1000 to 2500 as in the case of the thermosetting resin. There is 300
It was no exaggeration to say that there was nothing more than zero. The cause is nothing but the conventional direct esterification method of a polybasic acid or its acid anhydride and a polyhydric alcohol, even if trying to achieve a number average molecular weight higher than the above, gelation could not be achieved. . In the synthesis of thermoplastic polyester, there may be cases where a general deglycolization reaction, that is, a high temperature of 250 ° C. or higher, a high reduced pressure of 1 mmHg or less, and the use of a metal compound catalyst were tried,
The present inventors also tried to synthesize a high molecular weight unsaturated alkyd under these conditions, but even if a large amount of a polymerization inhibitor was added, gelation was unavoidable and it ended in failure. Under the general conditions for the synthesis of thermoplastic polyesters, it is clear that thermosetting unsaturated alkyds cannot be synthesized, and there is an essential difference between the two. I can't find any cases where it was announced that the unsaturated alkyd synthesis was successful. For example, in the case of thermoplastic polyester, as shown in FIGS. 1 and 2, both the number average molecular weight and the weight average molecular weight decrease after the optimum reaction conditions. In other words, it suggests that a decomposition reaction is occurring. On the contrary, in the unsaturated alkyd, as shown in FIG. 3, the number average molecular weight becomes constant when it is slightly lower than the maximum value, whereas the weight average molecular weight is seen in FIG. It has been increasing steadily. This shows that the unsaturated alkyds are cross-linked simultaneously with the decomposition, and it is clear that there is an essential difference in the reaction from these viewpoints.

[0003]

As a result of various investigations, the present inventors have found a method for obtaining an unsaturated alkyd having a number average molecular weight of 5000 or more by the following method. That is, the first aspect of the present invention comprises [A] (1) an α, β-unsaturated polybasic acid or an acid anhydride thereof as a component, and the use ratio thereof is a saturated or unsaturated polybasic acid used in combination. 10 mol% based on the total of 100 mol% with the acid (or its acid anhydride)
And the above, and (2) polyhydric alcohol having a boiling point of 300 ° C. or less at 760 mmHg of 50 mol% or more based on 100 mol% in total of the polyhydric alcohol used in combination with Then, the number average molecular weight obtained by deglycolization reaction is 5
000 or more, to the unsaturated alkyd having a hydroxyl group as a terminal group, [B] trimellitic anhydride is added to
10 mol% or more of the terminal groups obtained by reacting 10 mol% or more with respect to the hydroxyl group in the unsaturated alkyd of [A] is represented by the formula (1)

[0004]

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An unsaturated alkyd characterized by being occupied by the group A second aspect of the present invention relates to a high molecular weight unsaturated polyester resin in which the unsaturated alkyd obtained as described above is blended with a monomer that can be copolymerized with the unsaturated alkyd.

More specifically, in the present invention, first, in the step [A], (1) an α, β-unsaturated polybasic acid or an acid anhydride thereof is contained as a component, and any saturated or unsaturated polybasic acid is contained. Alternatively, (2) a hydroxyl polyester 1 having an acid value of 15 or less and a number average molecular weight of 500 or more, which is obtained by esterifying with a polyhydric alcohol in combination with the acid anhydride.
0.01 part by weight or more of an organotitanium compound catalyst is added to 00 parts by weight, and a deglycolization reaction is performed under a reduced pressure of 5 mmHg or less to synthesize a high molecular weight unsaturated alkyd having a number average molecular weight of 5000 or more. During this [A] stage reaction,
The proportion of the α, β-unsaturated polybasic acid (or its acid anhydride) used is 10 mol% or more of the entire polybasic acid (or its anhydride). As the polyhydric alcohol used in this reaction, one having a boiling point of 300 ° C./760 mmHg or less is 50 mol% or more of the total polyhydric alcohol used. The reason why the use ratio of the α, β-unsaturated polybasic acid (or its anhydride) is limited to 10 mol% or more is that when it is less than 10 mol%, the physical properties, particularly the mechanical properties of the cured resin, are rapidly lowered, This is because the curability also deteriorates and it becomes difficult to completely cure. The reason for defining the boiling point of the polyhydric alcohol is that if there are many polyhydric alcohols having a higher boiling point than this, the deglycolization reaction becomes difficult to occur and it becomes difficult to increase the molecular weight. The high boiling point polyhydric alcohol which cannot be expected to undergo a deglycolization reaction can be used only at a use ratio of 50 mol% or less.

Next, in step [B], the molecular end of the unsaturated alkyd is modified with trimellitic anhydride. The reasons and effects are as follows. In comparison with general low-molecular weight unsaturated alkyds synthesized by esterification having a carboxyl group and a hydroxyl group as terminal groups, a high molecular weight is obtained by deglycolization reaction as in [A]. Inevitably, the end groups of high molecular weight unsaturated alkyds are mostly hydroxyl groups. It may be used even if the hydroxyl group is a terminal group without any problem, for example, casting, but it may be practically supported if at least a part of the hydroxyl group is not a carboxyl group. For example, SMC (Sheet Molding Compoun
This is the case, for example, in the case of d) and BMC (Bulk Molding Compound), in which a terminal carboxyl group is reacted with an oxide or hydroxide of a divalent metal to increase the molecular weight to obtain a molding material. However, if a general polybasic acid is added for esterification in order to carboxylate a part of the terminal hydroxyl group, there is a risk of lowering the molecular weight due to decomposition of the unsaturated alkyd, which is a practical problem. We have
Trimellitic anhydride of the following formula (2)

[0008]

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Add a predetermined amount at the required temperature, and further add 5 mmHg
By treating with the following reduced pressure, a part or all of the terminal hydroxyl groups are modified without decreasing the molecular weight, and as shown in the following formula (3),

[0010]

[Chemical 4]

It has been found that it is possible to form benzenedicarboxylic acids each having a carboxyl group at the meta position. When the terminal group of the conventional low molecular weight unsaturated alkyd is formed into such a shape, the ratio of the terminal group becomes too high, resulting in impaired water resistance and alkali resistance of the resulting unsaturated polyester resin, and mixing with a filler. As a result, the kneaded material is solidified and becomes unmoldable. However, in the high molecular weight unsaturated alkyd having a number average molecular weight of 5,000 or more according to the present invention, the ratio of the terminal groups is lowered, so that such a defect is alleviated. As a result, it is possible to obtain an unsaturated polyester resin having a high molecular weight, good miscibility with the filler, and excellent mechanical properties and chemical resistance.

The raw material of the polybasic acid for synthesizing the high molecular weight unsaturated alkyd according to the present invention is no different from that for the conventional production of unsaturated alkyd. Examples of the raw materials to be used include the following. (A) As the α, β-unsaturated polybasic acid and its acid anhydride, maleic anhydride, fumaric acid, itaconic acid and the like are practically used. (B) Saturated or unsaturated polybasic acids (or acid anhydrides thereof) include those having a benzene nucleus, such as phthalic anhydride, isophthalic acid, terephthalic acid, and dimethyl ester, and aliphatic cyclic polybasic acids. Or as the acid anhydride thereof, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, het acid, and the like, further as an aliphatic dicarboxylic acid, Examples thereof include succinic acid, adipic acid, azelaic acid and sebacic acid. Examples of the halogen-containing acid include tetrachlorophthalic anhydride, tetrabromophthalic anhydride, and the like, in addition to hettic acid.

Polyhydric alcohols having a boiling point of 300 ° C./760 mmHg or less include, for example, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, butanediol 1,3, butanediol 1,3.
4, neopentyl glycol, 2, ethyl-2 methylpropanediol 1,3, pentanediol 1,5, hexanediol 1,6, and further, as alkylene monoepoxy compounds, ethylene oxide, propylene oxide, epichlorohydrin, phenyl Examples thereof include glycidyl ether and allyl glycidyl ether. The following types of polyhydric alcohols, which have a high boiling point and which are difficult to exchange with glycol, can be used in a combined form of 50 mol% or less. That is, examples of the high boiling point polyhydric alcohol include hydrogenated bisphenol A, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, glycerin diallyl ether, and trimethylolpropane mono- or diallyl ether.

The synthesis of the high molecular weight unsaturated alkyd according to the present invention is carried out by esterification as the first step, deglycolization reaction as the second step, and carboxylation by addition of trimellitic anhydride as the third step. The first-stage esterification is carried out according to a conventional method in an inert gas stream at 160
It is carried out at a temperature of ˜230 ° C. and is carried out by substantially synthesizing a hydroxyl polyester with an acid value of 15 or less, preferably 10 or less. As described above, the number average molecular weight at this time is 500 or more. The deglycolization reaction (transesterification reaction) in the second step is carried out in the presence of a catalyst,
It is carried out under a high reduced pressure of 5 mmHg, preferably 1 mmHg or less. At this time, if the acid value exceeds 15, the deglycolization reaction is not sufficiently carried out, and as a result, it becomes difficult to synthesize the desired high molecular weight unsaturated alkyd. As the catalyst, an organic compound of titanium can be used. For example, tetrabutyl titanate, tetrapropyl titanate, titanium acetylacetonate. The amount used is 0.01 to 0.5 parts by weight based on 100 parts by weight of the hydroxyl polyester,
Desirably, it is 0.1 to 0.3 parts by weight. The proportion of carboxyl groups is 10 mol or more in mol% of the entire terminal groups. Below this, the substantial meaning of introducing a carboxyl group is poor. The most suitable range naturally varies depending on the use, but is 30 mol% or more and 90 mol% or less. As a matter of course, since the number of end groups per unit weight varies depending on the molecular weight, the number average molecular weight in the present invention is 4 × 10 ^{6 for} GPC (column Showdex, No. KF-805 type, exclusion limit molecular weight polystyrene). ) Assuming that both ends of the measured average molecular weight are hydroxyl groups, a polybasic acid anhydride necessary for introducing a desired amount of a carboxyl group is added at the reaction temperature at the end of the deglycolization reaction.

Styrene is a typical monomer for dissolving the unsaturated alkyd to give the unsaturated polyester resin, but in addition, vinyltoluene, methyl methacrylate, diallyl phthalate, diallyl terephthalate,
Are used. The high molecular weight unsaturated polyester resin according to the present invention can be utilized in the applications where the general type unsaturated polyester resin has hitherto been utilized. In that case, it is needless to say that a fiber reinforcing material, a filler, a coloring agent, a release agent and a stabilizer can be used together.

[0016]

EXAMPLES Examples will be shown below to facilitate understanding of the present invention. In the examples, “parts” means “parts by weight” unless otherwise specified. Example 1 A propylene glycol 7 was placed in a 3 l separable flask equipped with a stirrer, a fractionating condenser, a thermometer, and a gas introduction tube.
Charged 75 g and 996 g of isophthalic acid, and in a nitrogen stream 18
After esterification at 5 to 195 ° C to an acid value of 24.7,
Fumaric acid (464 g) was added to proceed the esterification to an acid value of 9.2. The number average molecular weight was about 2000. Tetraisopropyl titanate (5 g) and hydroquinone (1 g) were added to this, the condenser was changed, and the deglycolization reaction was carried out by finally reducing the pressure to 0.8 mmHg at 205 to 210 ° C.
Finally, the number average molecular weight was 7,600. It was determined that this product had substantially no acid value and the terminal group was a hydroxyl group. 900 g of this unsaturated alkyd was dissolved in 900 g of styrene, and a high-molecular-weight unsaturated polyester resin (A) having hydroxyl groups as terminal groups was obtained with a Gardner color number of 3 and a viscosity of 7.9 poises. To the remaining unsaturated alkyd, 38 g of trimellitic anhydride (corresponding to about 0.8 mol per 1 mol of the terminal OH group) was added to give 205-210.
The mixture was heated and stirred at 30 ° C. for 30 minutes. The acid value of this product was 25. This was dissolved in 930 g of styrene to obtain a terminal carboxylated high molecular weight unsaturated polyester resin (B) with a Gardner color number of 4 and a viscosity of 9.1 poise. The molecular weight distribution during this reaction is summarized in Figure 5. According to FIG. 5, it was found that the molecular weight distributions were almost the same even after the terminal carboxylation reaction, and it was considered that there was no residual trimellitic anhydride added since there was no low molecular weight region. High molecular weight unsaturated polyester resin (A), terminal carboxylated high molecular weight unsaturated polyester resin (B) 1 each
100 parts of calcium carbonate was added to 00 parts, kneaded well, and left at room temperature. The viscosity after 1 week was as follows. Viscosity immediately after kneading Viscosity after 1 week (poise) (poise) Polyester resin (A) 131 159 Polyester resin (B) 281 ≈ 50,000 That is, according to the present invention, an aromatic group having two carboxyl groups at the meta position. It is clearly seen that the high molecular weight unsaturated polyester resin (B) modified by (2) is remarkably thickened by the combined use of calcium carbonate.

Example 2 100 parts of each unsaturated polyester resin produced in Example 1 was kneaded with 100 parts of calcium carbonate and 1 part of benzoyl peroxide, and after defoaming, cast into a thickness of 3 mm, 60 ° C. 2
The cast plate was prepared by curing at 80 ° C. for 2 hours and 120 ° C. for 2 hours, and tested. When the bending strength was measured, a difference was found between the casting plate using polyester resin (A) 8.9 kg / mm ^{2 and the} casting plate using polyester resin (B) 10.8 kg / mm ² .

EXAMPLE 3 Ethylene glycol 37 was placed in a 3 l separable flask equipped with a stirrer, a fractionating condenser, a thermometer, and a gas introduction tube.
2 g, neopentyl glycol 600 g, dimethyl terephthalate 776 g, and zinc acetate 5 g were charged.
After completion of the demethanol reaction at 180 ° C., 492 g of endomethylenetetrahydrophthalic anhydride and 294 g of maleic anhydride were added, and esterification was further continued to finally give an acid value of 8.7. The number average molecular weight at this stage is 220
It was 0. 6g of tetraisopropyl titanate
, 1 g of hydroquinone, 205-210 ° C
Finally, the number average molecular weight was 7900 at a reduced pressure of 0.8 mmHg.
The deglycolization reaction was allowed to proceed. This had an acid value of substantially zero. 1050 g of the unsaturated alkyd having terminal hydroxyl groups was dissolved in 1050 g of styrene to obtain a high-molecular-weight unsaturated polyester resin (C) having a Gardner color number of 4 and a viscosity of 10.9 poise. To the remaining unsaturated alkyd, add 30 g of trimellitic anhydride (amount that converts all the terminal hydroxyl groups to carboxyl groups), and add 20
It was kept under a reduced pressure of 5-210 ° C. and 1.1 mmHg for 30 minutes. The number average molecular weight increased slightly to 8400 and the acid value was 1.
It was 7.2. This was dissolved in 1100 g of styrene to obtain a high molecular weight unsaturated polyester resin (D) with a Gardner color number of 5 and a viscosity of 16.1 poise. As a test piece for adhesion test, surface-polish with # 1000 polishing paper,
150 × 15 surface-cleaned in 1-trichloroethane vapor
Using 0 × 3 mm steel plate, 100 parts of calcium carbonate, 1.5 parts of methyl ethyl ketone peroxide, 100 parts of each resin for 12 mm of the end, cobalt naphthenate (6%)
Co) 0.8 part was added, and the system defoamed under reduced pressure was applied and adhered. The adhesive strength by tensile shearing after standing for 48 hours was found to be 89.0 (kg / cm ² ) when using polyester resin (C) and 113 (kg / cm ² ) when using polyester resin (D). .

[0019]

Since the present invention is constituted as described above, it is possible to obtain a high molecular weight unsaturated polyester resin having a terminal modified with benzenedicarboxylic acid, and because of its excellent mechanical and chemical properties. It can be applied to various applications such as casting, paint, and adhesion.

[Brief description of drawings]

FIG. 1 shows the relationship between the reduced pressure reaction time and the molecular weight distribution (number average) of high-molecular-weight saturated polyester.

FIG. 2 shows the relationship between the reduced pressure reaction time and the molecular weight distribution (weight average) of high molecular weight saturated polyester.

FIG. 3 shows the relationship between the reaction time under reduced pressure and the molecular weight distribution (number average) of high molecular weight unsaturated alkyd.

FIG. 4 shows the relationship between the reaction time under reduced pressure and the molecular weight distribution (weight average) of high molecular weight unsaturated alkyd.

5 shows the molecular weight distribution during the reaction in Example 1. FIG.

Claims (2)

[Claims] 1. [A] (1) An α, β-unsaturated polybasic acid or an acid anhydride thereof is contained as one component, and the use ratio thereof is
10 mol% or more based on a total of 100 mol% with a saturated or unsaturated polybasic acid (or its acid anhydride) used in combination, and (2) the boiling point at 760 mmHg is 3
A number average obtained by esterifying a polyhydric alcohol having a temperature of 00 ° C. or lower with a polyhydric alcohol containing 50 mol% or more with respect to a total of 100 mol% of the polyhydric alcohol used in combination and then performing a deglycol reaction. Molecular weight is 500
[B] trimellitic anhydride is added to an unsaturated alkyd having a hydroxyl group of 0 or more and a terminal group being substantially a hydroxyl group, [A]
10 mol% or more of the terminal groups obtained by reacting 10 mol% or more with respect to the hydroxyl group in the unsaturated alkyd of the formula (1) Unsaturated alkyd, characterized by being occupied by groups of 2. The unsaturated alkyd according to claim 1,
A high molecular weight unsaturated polyester resin containing a monomer capable of being copolymerized therewith.